Indoor location services using a distributed lighting network

ABSTRACT

A method includes the steps of obtaining distance measurements between a device and a number of lighting fixtures, processing the distance measurements to assign coordinates to each one of the lighting fixtures, and facilitating registration of the coordinates of a subset of the lighting fixtures to obtain registered coordinates for all of the lighting fixtures. The coordinates indicate a relative location of each one of the lighting fixtures with respect to one another. The registered coordinates indicate a location of each lighting fixture in a desired coordinate space. Accordingly, a location of a lighting fixture within a desired coordinate space can be easily obtained, which may enable significant additional functionality of the lighting fixture.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/832,341, filed Dec. 5, 2017, which claims priority to and is acontinuation-in-part of U.S. patent application Ser. No. 15/192,035,filed Jun. 24, 2016, now U.S. Pat. No. 10,251,245, which claims thebenefit of U.S. provisional patent application Ser. No. 62/292,528,filed Feb. 8, 2016, the disclosures of which are hereby incorporatedherein by reference in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to the automatic mapping of devices in adistributed lighting network and the utilization of mapped devices in adistributed lighting network to provide indoor location services to auser.

BACKGROUND

Lighting fixtures continue to evolve, incorporating features such assensors, processing circuitry, networking circuitry, and the like.Accordingly, lighting fixtures may implement lighting programs, respondto the surrounding environment, and be controlled, for example, over alocal area network and/or the Internet.

Thus far, lighting fixtures have been primarily concerned with measuringenvironmental factors directly related to the light output thereof(e.g., ambient light and occupancy). These environmental factors havegenerally been used to make decisions locally, for example, regardingthe light output level of the lighting fixture to which the sensors areattached.

Networking circuitry has been incorporated into many lighting fixturesto allow them to communicate with one another. For example, a commonapproach is to form a mesh network of lighting fixtures in which thelighting fixtures can communicate with one another and/or receivecommands from remote devices. Generally, these lighting fixture networksare used to provide control commands to various lighting fixtures orgroups of lighting fixtures to adjust the light output thereof in somemanner.

While the above mentioned features may improve the utility of a lightingfixture or group of lighting fixtures, there are significantopportunities for improvement.

SUMMARY

The present disclosure relates to the automatic mapping of devices in adistributed lighting network and the utilization of mapped devices in adistributed lighting network to provide indoor location services to auser. In one embodiment, a distributed lighting network includes anumber of lighting fixtures and an indoor location services module. Eachof the lighting fixtures has a known location in an indoor space, andprovides a wireless beacon signal, where the wireless beacon signalidentifies the lighting fixture from which it is provided and indicatesa distance between a receiver of the wireless beacon signal and thelighting fixture form which the signal was provided. The indoor locationservices module determines a location of a mobile device in the indoorspace based on information about each wireless beacon signal received bythe mobile device and the known location of the lighting fixtures. Usingthe lighting fixtures to provide the wireless beacon signals, each ofwhich has a fixed, known location, allows for highly accurate indoorlocation services for the mobile device.

In one embodiment, the location of each one of the lighting fixtures inthe distributed lighting network is automatically determined byobtaining a first set of distance measurements and a second set ofdistance measurements and processing the first set of distancemeasurements and the second set of distance measurements to assigncoordinates to each one of the lighting fixtures. The first set ofdistance measurements are obtained using a first measurement method. Thesecond set of distance measurements is obtained using a secondmeasurement method, which is different from the first measurementmethod. By using both the first set of distance measurements and thesecond set of distance measurements, each of which is obtained by adifferent measurement method, the location of each one of the lightingfixtures can be obtained with a high degree of accuracy, therebyallowing the lighting fixtures to be used to provide indoor locationservices to a mobile device.

Those skilled in the art will appreciate the scope of the presentdisclosure and realize additional aspects thereof after reading thefollowing detailed description of the preferred embodiments inassociation with the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The accompanying drawing figures incorporated in and forming a part ofthis specification illustrate several aspects of the disclosure, andtogether with the description serve to explain the principles of thedisclosure.

FIG. 1 is a block diagram of a distributed lighting network according toone embodiment of the present disclosure.

FIG. 2 is a functional schematic of a lighting fixture according to oneembodiment of the present disclosure.

FIG. 3 is a functional schematic of a sensor module according to oneembodiment of the present disclosure.

FIG. 4 is a functional schematic of a lighting fixture connected to asensor module according to one embodiment of the present disclosure.

FIG. 5 is a functional schematic of a controller according to oneembodiment of the present disclosure.

FIG. 6 is a functional schematic of a controller connected to a sensormodule according to one embodiment of the present disclosure.

FIG. 7 is a functional schematic of a border router according to oneembodiment of the present disclosure.

FIG. 8 is a functional schematic of a border router connected to asensor module according to one embodiment of the present disclosure.

FIG. 9 is a diagram illustrating a distributed lighting system accordingto one embodiment of the present disclosure.

FIG. 10 is a call flow diagram illustrating a process for automaticallygrouping a number of devices in a distributed lighting network accordingto one embodiment of the present disclosure.

FIG. 11 is a table indicating a detected link strength between lightingfixtures in a distributed lighting network.

FIG. 12 is a table indicating a neighbor ranking for each one of anumber of lighting fixtures in a distributed lighting network.

FIG. 13 is a flow diagram illustrating a process for adding devices to adistributed lighting network according to one embodiment of the presentdisclosure.

FIG. 14 is a diagram illustrating a distributed lighting systemaccording to one embodiment of the present disclosure.

FIG. 15 is a flow diagram illustrating a process for grouping devices ina distributed lighting network according to one embodiment of thepresent disclosure.

FIGS. 16A through 16C are diagrams illustrating a distributed lightingnetwork according to various embodiment of the present disclosure.

FIG. 17 is a call flow diagram illustrating a process for adjusting thelight output of one or more lighting fixtures in a distributed lightingnetwork according to one embodiment of the present disclosure.

FIGS. 18A through 18D are diagrams illustrating a distributed lightingnetwork according to various embodiments of the present disclosure.

FIG. 19 is a flow diagram illustrating a process for detecting devicesnear entrances and/or exits according to one embodiment of the presentdisclosure.

FIG. 20 is a flow diagram illustrating a process for determining andindicating a desired position of a border router in a distributedlighting network according to one embodiment of the present disclosure.

FIG. 21 is a flow diagram illustrating a process for calibrating one ormore ambient light sensors according to one embodiment of the presentdisclosure.

FIG. 22 is a call flow diagram illustrating a process for determiningand using an optimal communication channel in a distributed lightingnetwork according to one embodiment of the present disclosure.

FIG. 23 is a call flow diagram illustrating a process for determiningand using an optimal communication channel in a distributed lightingnetwork according to one embodiment of the present disclosure.

FIGS. 24A and 24B are flow diagrams illustrating a process for detectingoccupancy using an image sensor according to one embodiment of thepresent disclosure.

FIG. 25 is a flow diagram illustrating a process for adjusting a lightlevel of a lighting fixture in order to properly detect occupancy in alighting fixture according to one embodiment of the present disclosure.

FIG. 26 is a functional schematic of power converter circuitry accordingto one embodiment of the present disclosure.

FIG. 27 is a flow diagram illustrating a process for detecting andresponding to a commissioning tool using an image sensor according toone embodiment of the present disclosure.

FIG. 28 is a flow diagram illustrating a process for providing mergedimages from multiple image sensors in a distributed lighting networkaccording to one embodiment of the present disclosure.

FIG. 29 is a flow diagram illustrating a process for correlating imagedata and geospatial data and displaying the result according to oneembodiment of the present disclosure.

FIG. 30 is a flow diagram illustrating a process for mapping andregistering devices in a distributed lighting network according to oneembodiment of the present disclosure.

FIG. 31 is a diagram illustrating the process described in FIG. 30according to one embodiment of the present disclosure.

FIG. 32 is a diagram illustrating a lighting network communicationsmodule for use with a mobile device according to one embodiment of thepresent disclosure.

FIG. 33 illustrates an exemplary user interface for registering devicesin a distributed lighting network according to one embodiment of thepresent disclosure.

FIG. 34 is a flow diagram illustrating a process for mapping andregistering devices in a distributed lighting network according to oneembodiment of the present disclosure.

FIG. 35 is a diagram illustrating the process described in FIG. 34according to one embodiment of the present disclosure.

FIG. 36 is a flow diagram illustrating details of the process describedin FIG. 34 according to one embodiment of the present disclosure.

FIG. 37 is a flow diagram illustrating details of the process describedin FIG. 34 according to one embodiment of the present disclosure.

FIG. 38 is a flow diagram illustrating a process for adjusting a drivesignal to a light source in order to reduce the energy consumption of alighting fixture according to one embodiment of the present disclosure.

FIG. 39 is a diagram illustrating a process for adjusting a drive signalto a light source in order to reduce the energy consumption of alighting fixture according to one embodiment of the present disclosure.

FIG. 40 is a flow diagram illustrating a process for measuring anddetermining the power consumption of a device in a distributed lightingnetwork according to one embodiment of the present disclosure.

FIG. 41 is a flow diagram illustrating a process for reducing the powerconsumption of a device in a distributed lighting network according toone embodiment of the present disclosure.

FIGS. 42A and 42B illustrate a lighting fixture according to oneembodiment of the present disclosure.

FIG. 43 is a functional schematic of a lighting fixture according to oneembodiment of the present disclosure.

FIG. 44 is a functional schematic of a lighting fixture connected to asensor module according to one embodiment of the present disclosure.

FIG. 45 illustrates a lighting fixture according to one embodiment ofthe present disclosure.

FIG. 46 is a flow diagram illustrating a process for detecting anoptical indicator and adjusting settings based on the optical indicatoraccording to one embodiment of the present disclosure.

FIG. 47 is a flow diagram illustrating a process for determining one ormore environmental conditions based on sensor data measured by devicesin a distributed lighting network according to one embodiment of thepresent disclosure.

FIG. 48 is a flow diagram illustrating a process for adjusting one ormore building management system (BMS) parameters based on sensor datameasured by devices in a distributed lighting network according to oneembodiment of the present disclosure.

FIG. 49 is a call flow diagram illustrating a process for communicationbetween devices in a distributed lighting network according to oneembodiment of the present disclosure.

FIG. 50 is a call flow diagram illustrating a process for communicationbetween a remote device and the devices in a distributed lightingnetwork according to one embodiment of the present disclosure.

FIG. 51 is a flow diagram illustrating a process for transferringsettings between devices in a distributed lighting network according toone embodiment of the present disclosure.

FIGS. 52A and 52B illustrate a lighting fixture according to oneembodiment of the present disclosure.

FIG. 53 is a flow diagram illustrating a process for determining alocation of each lighting fixture in a distributed lighting networkaccording to one embodiment of the present disclosure.

FIGS. 54A and 54B illustrate details of the process for determining thelocation of each lighting fixture in the distributed lighting networkaccording to one embodiment of the present disclosure.

FIG. 55 illustrates a process for scaling and translating relativecoordinates of lighting fixtures into a real coordinate system accordingto one embodiment of the present disclosure.

FIG. 56 is a flow diagram illustrating a process for generating a map ofan indoor space from information collected by lighting fixtures in adistributed network according to one embodiment of the presentdisclosure.

FIG. 57 illustrates providing indoor location services from one or morelighting fixtures in a distributed lighting network to a mobile deviceaccording to one embodiment of the present disclosure.

FIG. 58 is a flow diagram illustrating a process for providing indoorlocation services to a mobile device in a distributed lighting networkaccording to one embodiment of the present disclosure.

FIG. 59 is a call flow diagram illustrating a process for providingindoor location services to a mobile device in a distributed lightingnetwork according to one embodiment of the present disclosure.

FIG. 60 illustrates providing indoor location services from one or morelighting fixtures in a distributed lighting network to a mobile deviceaccording to one embodiment of the present disclosure.

FIG. 61 is a flow diagram illustrating a process for providing indoorlocation services to a mobile device in a distributed lighting networkaccording to one embodiment of the present disclosure.

FIG. 62 is a call flow diagram illustrating a process for providingindoor location services to a mobile device in a distributed lightingnetwork according to one embodiment of the present disclosure.

DETAILED DESCRIPTION

The embodiments set forth below represent the necessary information toenable those skilled in the art to practice the embodiments andillustrate the best mode of practicing the embodiments. Upon reading thefollowing description in light of the accompanying drawing figures,those skilled in the art will understand the concepts of the disclosureand will recognize applications of these concepts not particularlyaddressed herein. It should be understood that these concepts andapplications fall within the scope of the disclosure and theaccompanying claims.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element such as a layer, region, orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present.Likewise, it will be understood that when an element such as a layer,region, or substrate is referred to as being “over” or extending “over”another element, it can be directly over or extend directly over theother element or intervening elements may also be present. In contrast,when an element is referred to as being “directly over” or extending“directly over” another element, there are no intervening elementspresent. It will also be understood that when an element is referred toas being “connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present.

Relative terms such as “below” or “above” or “upper” or “lower” or“horizontal” or “vertical” may be used herein to describe a relationshipof one element, layer, or region to another element, layer, or region asillustrated in the Figures. It will be understood that these terms andthose discussed above are intended to encompass different orientationsof the device in addition to the orientation depicted in the Figures.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes,” and/or “including” when used herein specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms used herein should be interpreted ashaving a meaning that is consistent with their meaning in the context ofthis specification and the relevant art and will not be interpreted inan idealized or overly formal sense unless expressly so defined herein.

FIG. 1 illustrates a distributed lighting network 10 according to oneembodiment of the present disclosure. The distributed lighting network10 includes a number of lighting networks 12, and in particular awireless lighting network 12A and a wired lighting network 12B. Thewireless lighting network 12A includes a number of devices 14, which maybe lighting fixtures 14A, sensor modules 14B, controllers 14C, andborder routers 14D. The devices 14 communicate with one another viawireless signals. In one embodiment, the devices 14 form a wireless meshnetwork, such that communication between two endpoints may beaccomplished via one or more hops. For example, the devices 14 maycommunicate with one another via Institute of Electrical and ElectronicsEngineers (IEEE) standard 802.15 or some variant thereof. Using awireless mesh network to communicate among the devices 14 may increasethe reliability thereof and allow the wireless lighting network 12A tospan large areas.

The wired lighting network 12B also includes a number of devices 14. Inaddition to including lighting fixtures 14A, sensor modules 14B,controllers 14C, and border routers 14D, the wired lighting network 12Bmay also include one or more switches 14E. In contrast to the wirelesslighting network 12A, the devices 14 in the wired lighting network 12Bcommunicate with one another via signals sent over a wired interface. Inparticular, the devices 14 may communicate with one another via anEthernet interface, which is facilitated by a switch 14E. There may bemultiple switches 14E in the wired lighting network 12B, each of whichis connected to a particular subset of the devices 14. In oneembodiment, the switches 14E are Power over Ethernet (PoE) switches suchas those conforming to IEEE standard 802.3. Accordingly, the switches14E may provide power to the devices 14 while simultaneouslyfacilitating the exchange of data between the devices 14. While each oneof the devices 14 are shown individually connected to a switch 14E, thedevices 14 may be connected to one another in any manner, such that oneof the devices 14 connects to one or more of the switches 14E via one ormore other devices 14.

Each border router 14D may be in communication with each other borderrouter 14D, or a subset of each other border router 14D. Suchcommunication may occur in a wired or wireless manner. Similarly, eachswitch 14E may be in communication with each other switch 14E, or asubset of each other switch 14E. At least one of the switches 14E is incommunication with at least one of the border routers 14D. The one ormore border routers 14D in communication with the one or more switches14E act as a bridge between the wireless lighting network 12A and thewired lighting network 12B, and therefore allow the separate networks tocommunicate with one another. Such bridge functionality may involvenetwork address translation, network protocol translation, and the like,which is facilitated by the border router 14D. While the border router14D in FIG. 1 is shown bridging the wireless lighting network 12A andthe wired lighting network 12B, the border router 14D may also bridgetwo or more separate wireless lighting networks 12A, two or more wiredlighting networks 12B, or any combination thereof. Further, whilemultiple border routers 14D are shown in FIG. 1, only a single borderrouter 14D may be provided in some embodiments. Generally, additionalborder routers 14D are provided to increase network reliability andspeed. Similarly, while multiple switches 14E are shown in FIG. 1, onlyone switch 14E may be provided in some embodiments. Generally,additional switches 14E are provided to support a larger number ofdevices 14, since the capacity of each switch 14E is limited. In oneembodiment, the functionality of the border router 14D and the switch14E is combined, such that each device 14 in the wired lighting network12B connects directly or indirectly to one of the border routers 14D(rather than connecting to one of the border routers 14D via a switch14E).

In addition to bridging the wireless lighting network 12A and the wiredlighting network 12B, one or more of the border routers 14D may alsoconnect to other communications networks such as the Internet. Further,one or more of the border routers 14D may interface, either directly orindirectly, with one or more remote devices 16 (e.g., a computer orwireless communications device). When communicating directly with theone or more border routers 14D, the one or more remote devices 16 may doso in a wired or wireless fashion, and in any number of communicationsstandards/protocols. When communicating indirectly with the one or moreborder routers 14D, the one or more remote devices 16 may do so via anaccess point 18 connected to the Internet, which is in turn connected tothe one or more border routers 14D. Once again, the one or more borderrouters 14D are responsible for translating the various networkaddresses, protocols, and the like between the different devices.

In addition to the bridge functionality discussed above, one or more ofthe border routers 14D may also communicate with a building managementsystem 20, such as those conventionally used to control HVAC, security,and other building systems. Accordingly, one or more of the borderrouters 14D may include specialty communications circuitry forcommunicating with the building management system 20 in a wired orwireless manner. In another embodiment, the building management system20 is fitted with a communication module (not shown) which enables wiredor wireless communications with one or more of the border routers 14D.Allowing one or more of the border routers 14D to communicate with thebuilding management system 20 may add significant intelligence to anexisting building management system 20, and may allow for detailedinsights regarding a space as well as energy and cost savings asdiscussed below.

The wireless and wired communications in the distributed lightingnetwork 10 may occur in any number of communicationsstandards/protocols. Additionally, the number of devices 14, borderrouters 14D, switches 14E, remote devices 16, and the like may bedifferent in various embodiments. Using one or more of the borderrouters 14D to bridge the wireless lighting network 12A and the wiredlighting network 12B extends the reach of the distributed lightingnetwork 10, which may increase the functionality thereof. Further, usingone or more of the border routers 14D to provide a bridge to othernetworks and devices may significantly increase the functionalitythereof as discussed below.

The devices 14 may use the distributed lighting network 10 tocommunicate with one another. For example, the devices 14 may exchangestatus information, sensor data, commands, and the like. Messages passedbetween the devices 14 may be individually addressed such that themessages are received by a single one of the devices 14, broadcast to asubset of the devices 14, or broadcast to all of the devices 14. Theborder routers 14D and/or switches 14E may collect and store informationfrom the devices 14. For example, the border routers 14D may collect andstore status information, sensor data, or the like from the devices 14.Further, the border routers 14D and/or switches 14E may relay commandsfrom the remote devices 16 to one or more of the devices 14, and mayfacilitate the collection of data from the devices 14 by the remotedevices 16, either by providing cached data located in local storage inthe border routers 14D or by requesting the data directly from thedevices 14. At least one border router 14D or a designated device incommunication with at least one border router 14D may provide anApplication Program Interface (API), which is made available to devicesconnected to the distributed lighting network 10. In one embodiment,relevant information regarding the functioning of each one of thedevices 14 (e.g., status information, sensor data, and the like) islocally cached for a period of time within each individual device. Itmay then be periodically retrieved and stored by one or more of theborder routers 14D, or may be retrieved by one or more of the borderrouters 14D in response to a request from one or more of the remotedevices 16. Each one of the devices 14 may also periodically broadcastrelevant operational information, which is received and stored by one ormore of the border routers 14D. Alternatively, operational informationregarding each one of the devices 14 is not cached, but real timeoperational information can be obtained when requested. Virtuallyendless configurations exist for the storage and retrieval ofinformation among the various components of the distributed lightingnetwork 10, all of which are contemplated herein.

Notably, each one of the devices 14 is capable of operatingindependently of the others, and thus does not need to connect to thedistributed lighting network 10 to function. For example, each one ofthe devices 14 may be capable of detecting the occurrence of anoccupancy event and responding thereto (by adjusting the light outputthereof in the case of a lighting fixture 14A), detecting changes in anambient light level of the space surrounding the device and respondingthereto (by adjusting the light output thereof in the case of a lightingfixture 14A). In other words, the control logic for each one of thedevices 14 is locally stored and executed, and does not require externalinput. When connected to the distributed lighting network 10, thecontrol logic of each one of the devices 14 may consider informationprovided via the distributed lighting network 10, and therefore thebehavior of each one of the devices 14 may be influenced by otherdevices 14 in the network and/or one or more of the remote devices 16.For example, upon detection of an occupancy event by one of the devices14, other devices 14 may respond to the detected occupancy event.

Similar to the above, a group of devices 14 may function together (e.g.,sharing information and communicating with one another) withoutconnecting to a border router 14D. In other words, the border router(s)14D do not directly facilitate communication between the devices 14.This is due to the local control of each device discussed above.Accordingly, a border router 14D may or may not be provided, or maybecome disconnected or otherwise non-operational without causing afailure of the devices 14. While the additional functionality of theborder router 14D may be lost (e.g., as a network bridge between othernetworks), the devices 14 may still benefit from communicating with oneanother and enjoy the functionality afforded by such communication.

FIG. 2 is a block diagram illustrating details of a lighting fixture 14Aaccording to one embodiment of the present disclosure. The lightingfixture 14A includes driver circuitry 22 and an array of light emittingdiodes (LEDs) 24. The driver circuitry 22 includes power convertercircuitry 26, communications circuitry 28, processing circuitry 30, amemory 32, and sensor circuitry 34. The power converter circuitry 26 isconfigured to receive an alternating current (AC) or direct current (DC)input signal (V_(IN)) and perform power conversion to provide aregulated output power to the array of LEDs 24. Notably, the powerconverter circuitry 26 may be configured such that the input signal(V_(IN)) is provided in whole or in part by a battery, such that thelighting fixture 14A is portable, capable of operating in emergenciessuch as power outages, and/or capable of being used in one or moreoff-grid applications as discussed below. In one embodiment, the powerconverter circuitry 26 is configured to provide a pulse-width modulated(PWM) regulated output signal to the array of LEDs 24. While not shown,a connection between the power converter circuitry 26 and each one ofthe communications circuitry 28, the processing circuitry 30, the memory32, and the sensor circuitry 34 may provide regulated power to theseportions of the driver circuitry 22 as well. The processing circuitry 30may provide the main intelligence of the lighting fixture 14A, and mayexecute instructions stored in the memory 32 in order to do so. Theprocessing circuitry 30 may thus control the amount of current, voltage,or both provided from the power converter circuitry 26 to the array ofLEDs 24. The communications circuitry 28 may enable the lighting fixture14A to communicate via wireless or wired signals to one or more otherlighting fixtures 14A, sensor modules 14B, controllers 14C, borderrouters 14D, switches 14E, or any other devices. The communicationscircuitry 28 may be coupled to the processing circuitry 30 such thatinformation received via the communications circuitry 28 can beconsidered and acted upon by the processing circuitry 30. The sensorcircuitry 34 may include any number of different sensors 36. Forexample, the sensor circuitry 34 may include one or more passiveinfrared (PIR) occupancy sensors, one or more ambient light sensors, oneor more microphones, one or more speakers, one or more ultrasonicsensors and/or transducers, one or more infrared receivers, one or moreimaging sensors such as a camera, a multi-spectral imaging sensor, orthe like, one or more atmospheric pressure sensors, one or moretemperature and/or humidity sensors, one or more air quality sensorssuch as oxygen sensors, carbon dioxide sensors, volatile organiccompound (VOC) sensors, smoke detectors, and the like, one or morepositioning sensors such as accelerometers, Global Positioning Satellite(GPS) sensors, and the like, one or more magnetic field sensors, or anyother sensors. The sensor circuitry 34 may be in communication with theprocessing circuitry 30 such that information from the sensors 36 can beconsidered and acted upon by the processing circuitry 30. In somesituations, the processing circuitry 30 may use information from thesensors 36 to adjust the voltage and/or current provided from the powerconverter circuitry 26 to the array of LEDs 24, thereby changing one ormore aspects of the light provided by the lighting fixture 14A. In othersituations, the processing circuitry 30 may communicate information fromthe sensors 36 via the communications circuitry 28 to one or more of thedevices 14 or one or more of the border routers 14D in the distributedlighting network 10, or to one or more of the remote devices 16. Instill other situations, the lighting fixture 14A may both change one ormore aspects of the light provided therefrom based on information fromthe one or more sensors 36 and communicate the information from the oneor more sensors 36 via the communications circuitry 28.

The array of LEDs 24 includes multiple LED strings 38. Each LED string38 includes a number of LEDs 40 arranged in series between the powerconverter circuitry 26 and ground. Notably, the disclosure is notlimited to lighting fixtures 14A having LEDs 40 arranged in this manner.The LEDs 40 may be arranged in any series/parallel combination, may becoupled between contacts of the power converter circuitry 26, orarranged in any other suitable configuration without departing from theprinciples described herein. The LEDs 40 in each one of the LED strings38 may be fabricated from different materials and coated with differentphosphors such that the LEDs 40 are configured to provide light havingdifferent characteristics than the LEDs 40 in each other LED string 38.For example, the LEDs 40 in a first one of the LED strings 38 may bemanufactured such that the light emitted therefrom is green, and includea phosphor configured to shift this green light into blue light. SuchLEDs 40 may be referred to as blue-shifted green (BSG) LEDs. The LEDs 40in a second one of the LED strings 38 may be manufactured such that thelight emitted therefrom is blue, and include a phosphor configured toshift this blue light into yellow light. Such LEDs 40 may be referred toas blue-shifted yellow (BSY) LEDs. The LEDs 40 in a third one of the LEDstrings 38 may be manufactured to emit red light, and may be referred toas red (R) LEDs. The light output from each LED string 38 may combine toprovide light having a desired hue, saturation, brightness, etc. Anydifferent types of LEDs 40 may be provided in each one of the LEDstrings 38 to achieve any desired light output. The power convertercircuitry 26 may be capable of individually changing the voltage and/orcurrent provided through each LED string 38 such that the hue,saturation, brightness, or any other characteristic of the lightprovided from the array of LEDs 40 can be adjusted.

The lighting fixture 14A may be an indoor lighting fixture or an outdoorlighting fixture. Accordingly, the distributed lighting network 10 mayinclude any number of both indoor and outdoor lighting fixtures.

FIG. 3 is a block diagram illustrating details of a sensor module 14Baccording to one embodiment of the present disclosure. The sensor module14B includes power converter circuitry 42, communications circuitry 44,processing circuitry 46, a memory 48, sensor circuitry 50, and anindicator light LED_I. The power converter circuitry 42 is configured toreceive an AC or DC input signal (V_(IN)) and perform power conversionto provide a regulated output power to one or more of the communicationscircuitry 44, the processing circuitry 46, the memory 48, and the sensorcircuitry 50. Notably, the power converter circuitry 42 may beconfigured such that the input signal (V_(IN)) may be provided at leastin part by a battery, such that the sensor module 14B is portable,suitable for one or more off-grid applications, and/or capable ofoperating in emergencies such as power outages. The processing circuitry30 may provide the main intelligence of the sensor module 14B, and mayexecute instructions stored in the memory 48 to do so. Thecommunications circuitry 44 may enable the sensor module 14B tocommunicate via wireless or wired signals to one or more other lightingfixtures 14A, sensor modules 14B, controllers 14C, border routers 14D,switches 14E, or other devices. In some embodiments, regulated power isreceived at the communications circuitry 44 (e.g., via a communicationsinterface providing both power and data such as an Inter-IntegratedCircuit (I²C) bus, a universal serial bus (USB), or PoE), where it isthen distributed to the processing circuitry 46, the memory 48, and thesensor circuitry 50. Accordingly, in some embodiments, the powerconverter circuitry 42 may not be provided in the sensor module 14B. Thecommunications circuitry 44 may be coupled to the processing circuitry46 such that information received via the communications circuitry 44may be considered and acted upon by the processing circuitry 46. Thesensor circuitry 50 may include any number of sensors 52 as discussedabove. The sensor circuitry 50 may be in communication with theprocessing circuitry 46 such that information from the sensors 52 can beconsidered and acted upon by the processing circuitry 46. The indicatorlight LED_I may provide status information to a user, for example, bychanging the intensity, color, blinking frequency, or the like. Further,the indicator light LED_I may be used to participate in an automaticgrouping process as discussed below.

It may be desirable to incorporate the sensor modules 14B into thedistributed lighting network 10 in order to fill gaps in sensor coveragefrom the sensors 36 in the lighting fixtures 14A. That is, the spacingbetween lighting fixtures 14A may leave gaps in sensor coverage, whichmay be filled by standalone sensor modules 14B. Additionally, the sensormodules 14B provide the ability to include sensors in locations in whichlighting fixtures are not provided, or where legacy lighting fixtures(e.g., incandescent or fluorescent lighting fixtures are providedinstead). Further, the flexibility of the sensor modules 14B may allowthem to be incorporated into pre-existing devices including access topower, such as legacy lighting fixtures, exit signs, emergency lightingarrays, and the like. Finally, since the sensor modules 14B do notinclude the LED array 24, they may be significantly less expensive tomanufacture, and therefore may allow sensors to be deployed throughout aspace at a reduced cost.

FIG. 4 is a block diagram illustrating details of a lighting fixture 14Aaccording to an additional embodiment of the present disclosure. Thelighting fixture 14A shown in FIG. 4 is similar to that shown in FIG. 2,except that the sensor circuitry 34 is removed from the driver circuitry22. In place of the sensor circuitry 34, the driver circuitry 22connects to a sensor module 14B, which is integrated into the lightingfixture 14A. The sensor module 14B is substantially similar to thatshown above in FIG. 3, but does not include the power convertercircuitry 42, since, in the current embodiment, power is supplied to thesensor module 14B via the communications circuitry 44 (e.g., via an I²C,USB, or PoE interface). However, the disclosure is not so limited. Thedriver circuitry 22 may maintain all or a portion of the sensors 36shown in FIG. 2 and the sensor module 14B may maintain the powerconverter circuitry 42 in some embodiments. Further, the sensor module14B may share one or more components with the driver circuitry 22 invarious embodiments. The sensor module 14B may be detachable from thelighting fixture 14A and thus upgradeable over time. Details of such anupgradeable lighting fixture 14A are described in co-pending U.S. patentapplication Ser. No. 14/874,099, the contents of which are herebyincorporated by reference in their entirety. As discussed in thisapplication, the sensor module 14B may connect to the driver circuitry22 via a connector in the lighting fixture 14A, and may aestheticallyblend with the appearance of the lighting fixture 14A when installed.

Connecting a sensor module 14B to a lighting fixture 14A in this mannerprovides several benefits. First and foremost, it is a modular approach,and thus foregoes the need for separate product lines with and withoutthe additional functionality of the sensor module 14B. Second, thesensor module 14B may be upgradeable without changing the lightingfixture 14A, for example, to add additional sensors and functionality tothe lighting fixture 14A. Third, the sensor module 14B may includeseparate processing circuitry 46 from the lighting fixture 14A. Sincethe processing power of the processing circuitry 30 may be limited, andsince it is desirable to avoid overloading and thus slowing thefunctionality of the processing circuitry 30 in the lighting fixture14A, having separate processing circuitry 46 for conditioning orotherwise operating on data from the sensors 52 in the sensor module 14Bmay be highly advantageous. In general, any number of sensors may bedirectly integrated with a lighting fixture 14A, separate from thelighting fixture 14A and connected in either a wired or wireless mannerthereto, or separate from the lighting fixture 14A and connected via anetwork interface to the lighting fixture 14A.

FIG. 5 is a block diagram illustrating details of a controller 14Caccording to one embodiment of the present disclosure. The controller14C is similar to the lighting fixtures 14A and sensor module 14Bdiscussed above, and includes power converter circuitry 54,communications circuitry 56, processing circuitry 58, a memory 60,sensor circuitry 62 with a number of sensors 64, and an indicator lightLED_I. The function of each of these components is similar to thatdiscussed above for the lighting fixtures 14A and sensor module 14B. Thecontroller 14C further includes a user interface 66 that allows forinteraction with the controller. The user interface 66 may include oneor more physical buttons, switches, dials, etc., or may include asoftware interface that is displayed on a screen or touch-enabledscreen. The user interface 66 is coupled to the processing circuitry 58such that input provided via the user interface 66 can be considered andacted upon by the processing circuitry 58. In one embodiment, thecontroller 14C is a wall-mounted switch that includes one or morepaddles that act as the user interface 66. For example, the controller14C may be a CWD-CWC-XX and/or CWS-CWC-XX wall controller manufacturedby Cree, Inc. of Durham, N.C. Similar to the sensor module 14B discussedabove, the controller 14C may also be configured to be powered at leastin part by a battery such that the controller is portable, suitable forone or more off-grid applications, and/or capable of operating inemergencies such as power outages.

FIG. 6 is a block diagram illustrating details of a controller 14Caccording to an additional embodiment of the present disclosure. Thecontroller 14C shown in FIG. 6 is similar to that shown in FIG. 5,except that the sensor circuitry 62 is removed. In place of the sensorcircuitry 62, the controller 14C connects to a sensor module 14B, whichis integrated into the controller 14C. The sensor module 14B issubstantially similar to that shown above in FIG. 3, but does notinclude the power converter circuitry 42, since, in the currentembodiment, power is supplied to the sensor module 14B via thecommunications circuitry 44 (e.g., via an I²C, USB, or PoE interface).However, the disclosure is not so limited. The controller 14C maymaintain all or a portion of the sensors 64 shown in FIG. 5 and thesensor module 14B may maintain the power converter circuitry 42 in someembodiments. Further, the sensor module 14B may share one or morecomponents with the controller 14C in various embodiments. The sensormodule 14B may be detachable from the controller 14C and thusupgradeable over time. As discussed above, providing the sensor module14B in this manner may forego the need for additional product lines,maintain upgradeability of the controller without changing the corehardware thereof, and provide additional processing resources.

FIG. 7 is a block diagram illustrating details of a border router 14Daccording to one embodiment of the present disclosure. The border router14D includes power converter circuitry 68, communications circuitry 70,processing circuitry 72, a memory 74, sensor circuitry 76, and anindicator light LED_I. As discussed above, the power converter circuitry68 may receive an AC or DC input signal (V_(IN)) and perform powerconversion to provide a converted output signal, which is used to powerthe communications circuitry 70, the processing circuitry 72, the memory74, and the sensor circuitry 76. The input signal (V_(IN)) may beprovided in whole or in part by a battery in some embodiments, such thatthe border router 14D is portable, suitable for one or more off-gridapplications, and/or capable of operating in emergencies such as poweroutages. The communications circuitry 70 allows the border router 14D tocommunicate with lighting fixtures 14A, sensor modules 14B, controllers14C, switches 14E, remote devices 16, and the like, and allows theborder router 14D to bridge the various networks discussed above withrespect to FIG. 1. Accordingly, the communications circuitry 70 in theborder router 14D may be more robust than the communications circuitryin the lighting fixtures 14A, sensor modules 14B, controllers 14C,switches 14E, and remote devices 16. In particular, while the lightingfixtures 14A, sensor modules 14B, controllers 14C, switches 14E, andremote devices 16 may communicate via a single communications protocolor a handful of communications protocols and thus include communicationscircuitry configured only to communicate in this manner, thecommunications circuitry 70 of the border router may supportcommunication in a large number of diverse communications protocols suchthat the border router 14D is capable of bridging these variousnetworks. The processing circuitry 72 provides the central intelligenceof the border router 14D, and may execute instructions stored in thememory 74 in order to do so. For example, the processing circuitry 72may facilitate the collection and storage of operational data from thelighting fixtures 14A, sensor modules 14B, and controllers 14C, andfurther may facilitate the API discussed above to allow remote devices16 to obtain said operational information. The sensor circuitry 76 mayinclude any number of sensors 78 such as those discussed above, so thatthe border router 14D may collect information from its own sensors 78 inaddition to those provided by the lighting fixtures 14A, sensor modules14B, and controllers 14C.

FIG. 8 is a block diagram illustrating details of a border router 14Daccording to an additional embodiment of the present disclosure. Theborder router 14D is substantially similar to that shown above in FIG.7, except that the sensor circuitry 76 is removed from the border router14D. In place of the sensor circuitry 76, the border router 14D connectsto a sensor module 14B, which is integrated into the border router 14D.The sensor module 14B is substantially similar to that shown above inFIG. 3, but does not include the power converter circuitry 42, since, inthe current embodiment, power is supplied to the sensor module 14B viathe communications circuitry 44 (e.g., via an I²C or PoE interface).However, the disclosure is not so limited. The border router 14D maymaintain all or a portion of the sensors 78 shown in FIG. 7 and thesensor module 14B may maintain the power converter circuitry 42 in someembodiments. Further, the sensor module 14B may share one or morecomponents with the border router 14D in various embodiments. The sensormodule 14B may be detachable from the border router 14D and upgradeableover time. As discussed above, providing the sensor module 14B in thismanner may forego the need for additional product lines, maintainupgradeability of the controller without changing the core hardwarethereof, and provide additional processing resources.

In many environments, there are logical divisions between spacestherein. For example, a logical way to divide a building is by floor.Generally, the different lighting networks 12 in the distributedlighting network 10 can be separated based on these logical divisions.In the case of a building, a first lighting network 12 may span all or aportion of a first floor, a second lighting network 12 may span all or aportion of a second floor, and so on. In general, floors are a good wayto separate these lighting networks 12 because there is a lesser needfor communication and cooperation between devices 14 located ondifferent floors. Accordingly, dividing the lighting networks 12 in thismanner reduces the overall traffic in each lighting network 14 and thusmay improve the performance thereof. One or more border routers 14D maybridge the various lighting networks 12 to form the distributed lightingnetwork 10. Communication between these lighting networks 12 in thedistributed lighting network 10 may only be used for particular messagesor types of communication (e.g., high priority communication or thelike), thereby allowing each lighting network 12 to remain encapsulatedand thus enjoy the aforementioned reductions in network traffic.

In addition to forming different lighting networks 12 in a space, it issometimes desirable to form groups of devices 14 as well. These groupsmay correspond, for example, with the devices 14 that are present withina particular room, group of rooms, or other logical sub-division ofspace. Grouping devices 14 together may cause them to share informationto a higher degree than other devices in a lighting network 12. In someembodiments, devices 14 in a group will respond to commands initiatedfrom a controller 14C in the group. Devices 14 outside the group willnot respond to said commands. Similarly, devices 14 in a group mayrespond to changes in the environment detected by one or more sensors ofone of the devices 14 in the group. Devices 14 outside the group willnot respond to said environmental changes unless detected by one of thedevices 14 in their own group. In general, grouping devices 14 may allowthem to behave as a unit, which may be desirable in many circumstances.Groups of devices may correspond with networking groups having differentprivileges. For example, a group of devices may behave as a sub-networkof a larger lighting network 12. Further, a group of devices may belongto a multicast IP group in which messages are distributed among devicesin the group and not outside the group.

While the above description highlights the advantages of dividing anumber of devices 14 into networks and groups, doing so has previouslybeen a time consuming and difficult process. Conventionally, devices 14have been grouped manually, requiring a significant investment of timeto set up these groups. Further, network formation processes havepreviously been over-inclusive, often extending a lighting network 12beyond a desired space and causing network congestion due to anunnecessarily large number of devices 14 in the lighting network 12.Previous solutions have significantly simplified the grouping oflighting fixtures using light modulation (referred to herein as“lightcasting/lightcatching”), as performed by current SmartCast™lighting fixtures manufactured by Cree, Inc. of Durham, N.C. Detailsregarding the automatic formation of groups in this manner are discussedin U.S. patent application Ser. No. 13/782,022, the contents of whichare hereby incorporated by reference in their entirety. While theautomatic grouping discussed above may be applied to any of the devices14 in the distributed lighting network 10 to significantly improve thesetup process of grouping devices 14 together, several improvements havesince been made that further simplify network and group formation asdiscussed below.

Previously, network formation (i.e., the inclusion of devices in alighting network 12) was a separate process than the automatic groupingprocess discussed above. However, setup of a lighting network 12 and oneor more groups within the lighting network 12 may be performed togetherin some embodiments. With reference to FIG. 9, a number of devices 14,which could be any combination of lighting fixtures 14A, sensor modules14B, controllers 14C, and/or border routers 14D, are uniquely referencedas devices A through R and shown in different rooms (RM1-RM4) in aspace. In particular, device A is located in a first room RM1, devicesB-E are located in a second room RM2, devices I, J, L, M, Q, and R arelocated in a third room RM3, devices N and O are located in a fourthroom RM4, and devices F, G, H, K, and P are located in a fifth room RM5,which may be a hallway. Using “lightcasting” and “lightcatching,” thedevices 14 may be automatically grouped into five different groups asdiscussed below.

FIG. 10 is a call flow diagram illustrating an exemplary automaticgrouping process according to one embodiment of the present disclosure.First, the automatic grouping process is initiated (step 200). Theautomatic grouping process may be initiated in any number of differentways. For example, the automatic grouping process may be initiated usinga handheld commissioning tool configured to communicate directly witheach device 14, may be initiated by a remote device 16 connected to thedistributed lighting network 10, or may be initiated by pressing aphysical button or otherwise activating a sensor on one of the devices14. In one embodiment, the automatic grouping process is initiated assoon as the device 14 is powered on. In any event, the automaticgrouping process is generally initiated starting with a single device14, and in particular a single lighting fixture 14A. Due to the natureof the automatic grouping process, the initiating device 14 must becapable of providing a modulated light signal (either visible or not).Generally, the lighting fixtures 14A are the only devices 14 in thedistributed lighting network 10 that are capable of doing so, however,devices such as sensor modules 14B and controllers 14C may be similarlyconfigured to do so in some embodiments. Devices 14 that are not capableof providing such a modulated light signal may be configured to ignoresuch an initiation process or to handoff the initiation process to anearby device 14 (i.e., a lighting fixture 14A) that is capable of doingso. The initiating device 14 may be specifically chosen by a user,chosen at random, or selected in any preferred manner. In someembodiments, multiple devices 14 are simultaneously chosen to initiatethe automatic grouping process. This may speed up the automatic groupingprocess by allowing it to simultaneously propagate throughout a space inmultiple directions, but also may complicate the process, since it isnecessary to know which device 14 is providing the modulated lightsignal and there is a possibility that a single device 14 maysimultaneously see a modulated light signal from two different sources.Such a problem may be solved by each device 14 providing a modulatedlight signal at a particular frequency or frequency range in someembodiments. By communicating the frequency or frequency range usingwired or wireless communications, the devices 14 looking for modulatedlight signals can know which device 14 is providing which modulatedlight signal, and thereby determine the relationship between the devices14 as discussed below.

Regardless of how the initiating device(s) 14 are chosen, said device(s)14 first announce that they will begin providing a modulated lightsignal via wired or wireless communication (step 202). This lets otherdevices 14 in the network know which device(s) 14 are providing themodulated light signal upon detection. Accordingly, such an announcementmay include identifying information about the device(s) 14 providing amodulated light signal such as a device identifier or MAC address. Inadditional embodiments, each device 14 providing a modulated lightsignal may include an identifier thereof in the modulated light signalitself. This principle may be used to uniquely identify severaldifferent devices 14 that are simultaneously providing modulated lightsignals. In general, any desired information can be communicated in themodulated light signals provided by the devices 14, which may be usefulin streamlining the automatic grouping process. Next, the initiatingdevice(s) 14 begin providing the modulated light signal (“lightcasting”)at a particular frequency (step 204), while all other devices 14 in thenetwork detect the intensity of the modulated light signal(“lightcatching”) using one or more sensors (step 206). In oneembodiment, the detecting devices 14 detect the intensity of themodulated light signal using an ambient light sensor. Such a sensor iscapable of detecting the modulated light signal and a “signal strength”(i.e., a light intensity) thereof. In other embodiments, the detectingdevices 14 detect the intensity of the modulated light signal using animage sensor such as a camera. The image sensor may providesignificantly more information about the modulated light signal, such asa “signal strength” and a direction vector indicating the direction ofthe device 14 providing the modulated light signal with respect to thedetecting device 14. Accordingly, in some embodiments the detectingdevices 14 may similarly detect this additional information. Thedirection vectors discussed above may allow the devices 14 to determinea real-space representation of the devices 14 with respect to oneanother, as discussed in detail in co-pending U.S. patent applicationSer. No. 14/826,892, the contents of which are hereby incorporated byreference in their entirety.

The above described process is iterated such that each device 14 capableof providing a modulated light signal does so, and each other device 14obtains an intensity value associated with the modulated light signalfrom each one of these devices 14. The resulting data can be viewed as atable such as the one shown in FIG. 11. Notably, each device 14 may onlyknow the modulated light intensity measurements detected by its ownsensors, and thus in some embodiments the devices 14 may eitherperiodically share the relative intensity information with one anotherand with one or more remote devices 16 (step 208).

By normalizing and/or otherwise operating on the intensity data from thedevices 14, a link table such as the one shown in FIG. 12 can beobtained (step 210). For example, the light detected from a neighboringlighting fixture 14A may first be divided by the light detected from areceiving lighting fixture 14A to calibrate the light measurements tothe environment. Mutual light levels detected by neighboring lightingfixtures 14A may be averaged (e.g., the light level detected by a firstlighting fixture 14A from a second lighting fixture 14A may be averagedwith the light level detected by the second lighting fixture 14A by thefirst lighting fixture 14A) to calibrate for differences in device 14spacing and mounting heights. The light detected from a neighboringlighting fixture 14A may then be divided by the light detected from thenearest neighboring lighting fixture 14A (e.g., the light detected byneighboring lighting fixtures 14A may be divided by the strongestdetected light signal) in order to group together devices 14 with strongconnections. The relative light intensity detected by each device 14 maythen be examined to determine a threshold for grouping. This informationmay then be shared among neighboring devices 14 (step 212).

The above may be a distributed process performed at least in part byeach device 14, may be determined by a single device 14 and provided toall other devices 14, or may be determined by a remote device 16 andprovided to all other devices. The link table indicates the adjacency ofdevices in the network, such that the number indicates the number ofdevices 14 between any two devices 14 in the network. In someembodiments, each device 14 stores only the links that it shares withother devices 14. In other embodiments, each device 14 stores the entirelink table for the network. Devices 14 that are linked are grouped, suchas device A with itself, devices B-E with one another, devices F, G, H,K, and P with one another, devices I, J, L, M, Q, and R with oneanother, and devices N and O with one another. In this way, groupingbetween the devices 14 can be accomplished automatically.

In addition to the automatic grouping discussed above, any device 14that is seen by any other device 14 in the automatic grouping process isadded to a lighting network 12. As discussed above, a lighting network12 may define a first level of communication among devices, while agroup may define a second and more intensive level of communicationamong devices. Further, a distributed network such as the distributedlighting network 10 may define a third, less intensive level ofcommunication among devices 14 therein. Adding only those devices 14 tothe lighting network 12 that are in optical communication with oneanother may provide several benefits as discussed above. For example,doing so may prevent the over-inclusion of devices 14 into the lightingnetwork 12 and thus prevent over-congestion. Generally, opticalcommunication is a good analogue for devices 14 in a lighting network 12that will want or need to communicate. Accordingly, forming a lightingnetwork 12 in this manner may be highly advantageous. In some cases,certain devices 14 that should be included in a network may be opticallyisolated from other devices 14 (e.g., may be located behind a closeddoor). Such devices 14 may be added to the network manually as they areidentified, for example, by a commissioning tool or a remote device 16.Alternatively, the automatic grouping process described above may beperiodically and/or persistently performed, such that when the isolateddevice 14 is able to optically communicate with another device 14 in thenetwork (e.g., when a door is opened), the isolated device 14 isautomatically added to the network. Periodically and/or persistentlyperforming the automatic grouping process may further increase theaccuracy of automatic network and group formation over time, therebyreducing the effort required to setup the distributed lighting network10.

Periodically and/or persistently performing the automatic groupingprocess may be used to provide additional functionality as well. Forexample, information such as heartbeat signals, certain messages, andthe like may be broadcast via light modulation that is undetectable bythe human eye, which may reduce the number of messages sent over othernetwork means and thereby reduce network congestion. In someembodiments, light emitting devices in the network may communicatesolely via modulated light or may facilitate communication among anynumber of devices using modulated light. Further, the automatic groupingprocess may be used to detect entrances and exits within a space byexamining discontinuities in detection between devices 14. In short, ifa device 14 detects the modulated light signal from another device 14 ina discontinuous manner, this may indicate that a moveable obstacle suchas a door is between these devices 14, and thus may indicate that anentrance and/or exit is located between the devices. Determining whichdevices 14 are near entrances and/or exits may be useful in somesituations, as discussed in detail below.

As discussed above, any one of the lighting fixtures 14A, sensor modules14B, controllers 14C, and border routers 14D may include the necessaryhardware to detect modulated light (e.g., via an ambient light sensor,image sensor, or the like). Accordingly, any one of these devices 14 maybe added to a lighting network 12 substantially automatically, whichsignificantly simplifies the setup of the lighting network 12. In somesituations, supplemental information from other sensors in the devices12 may be used to assist in the network formation and grouping processdiscussed above. For example, atmospheric pressure sensor measurementsmay be analyzed to determine which devices should join a particularnetwork. As discussed above, a floor of a building is generally a goodway to define the boundaries of a lighting network. In some scenarios,however, the automatic grouping process discussed above may fail toinclude every device in the network, or may include devices in alighting network 12 that are not desired. This may be the case, forexample, in an open atrium in which devices 14 on different floors maysee the light provided by one another, or when a device 14 is opticallyisolated as discussed above. Accordingly, FIG. 13 is a flow diagramillustrating a method for including devices in a network with oneanother according to one embodiment of the present disclosure.

To begin, a first device counter (i) and a second device counter (j) areinitialized (step 300). A number of atmospheric pressure measurementsare then received from a first device 14 indicated by the first devicecounter and a second device 14 indicated by the second device counter(step 302). Next, a determination is made regarding whether or not adifference between the atmospheric pressure measurements for the firstdevice 14 and the second device 14 are within a predetermined distanceof one another (step 304). This may indicate, for example, that thedevices 14 are located on the same floor in a building. In general,ceiling mounted devices 14 such as lighting fixtures 14A will have verysimilar atmospheric pressure measurements (atmospheric pressure sensorsare generally capable of detecting a difference between a few verticalfeet). Devices 14 that are less than a predetermined distance belowthese ceiling mounted devices (e.g., sensor modules 14B, controllers 14Cand border routers 14D) are most likely also located on the same floor.Accordingly, if the atmospheric pressure measurements (or the average ofatmospheric pressure measurements) of two different devices 14 arewithin the predetermined distance of one another, the devices 14 areadded to the same network (step 306). If the atmospheric pressuremeasurements are not within the predetermined distance of one another,the second device counter is incremented (step 308) and a determinationis made regarding whether the second device counter is greater than thetotal number of devices in the lighting network 12 (step 310). If thesecond device counter is greater than the number of devices 14 in thelighting network 12, the network setup process is exited (step 312). Ifthe second device counter is not greater than the number of devices 14in the lighting network, the process returns to step 300.

The process may be performed in response to a command to initiatenetwork formation, as discussed above, which may be provided in anynumber of different ways. In response, the devices 14 may measure anatmospheric pressure and share this information among each other or withthe remote device 16. The process above may then be performed at anylevel of granularity to determine which devices 14 should be included ina particular network. Using the above process may significantly simplifythe setup of a network when used alone. Further, the above process maybe used in conjunction with the automatic grouping process describedabove to increase the accuracy thereof. For example, when used inconjunction with the automatic grouping process, the above process mayallow devices 14 that are optically isolated from other devices (e.g.,in a closet) to join the network. In addition to atmospheric pressure,any other sensor measurements may be combined with the “lightcasting”data obtained above in order to further increase the accuracy of theautomatic grouping process. For example, radio frequency ranging betweendevices 14 (e.g., time of flight ranging, phase difference ranging, orany other known RF ranging techniques) may be performed and used toverify or increase the accuracy of the automatic grouping process.

The initial groups established by the automatic grouping processdiscussed above may be further improved such that devices 14 in anetwork are more logically grouped in some situations. FIG. 14 shows anexample of such a scenario. In particular, FIG. 14 shows the samedevices 14 as in FIG. 9, but wherein the devices 14 are located in anopen space with minimal separation. For example, the devices 14 may belocated in a warehouse. Accordingly, grouping the devices 14 togethervia the automatic grouping process may result in placing all of thedevices 14 into a single group, since there are no optical barriers toseparate the devices 14. Since a warehouse or other open space may bequite large, and since only small portions of the space may be used atthe same time, such a grouping may be inefficient. For example, if allof the devices 14 are grouped together in FIG. 14, when one of thedevices 14 detects an occupancy event, all of the lighting fixtureslocated in the space may turn on. If only a small portion of the spaceis being used at this time, the space is then over-lit, thereby wastingenergy.

FIG. 15 is a flow diagram illustrating a method for dynamically groupingdevices 14 in a lighting network 12 over time by analyzing sensor datafrom one or more devices 14 in the distributed lighting network 10.First, sensor data is received from multiple devices 14 in a group orlighting network 12 (step 400). One or more desired patterns are thendetected in the sensor data (step 402). Examples of such patternsinclude occupancy events that are closely tied in time, occupancy eventsthat occur sequentially across a number of devices 14, sounds detectedby a number of different devices 14, changes in atmospheric pressuredetected by a number of different devices 14, changes in temperaturedetected by a number of different devices 14, changes in ambient lightlevels detected by a number of different devices 14, or some combinationthereof. Virtually any sensor data may be used to logically groupdevices. One or more devices 14 are then grouped together based on thedetected patterns in the sensor data (step 404).

Grouping devices in this manner allows devices 14 to dynamically formlogical groups based on the occupancy patterns within a space. Theforegoing process may be carried out by a single device 14, distributedamong a number of devices 14, or performed by a remote device 16. Usingdata obtained from the sensors of the various devices 14 to form groupsmay become even more accurate when done in a centralized manner by aremote device 16, as such a remote device 16 may have access to morehistorical data and processing power than a single device 14 alone. Forexample, performing dynamic grouping in a centralized manner may allowfor the application of machine learning algorithms, may provide accessto neural networks, or may otherwise provide additional resources thatare not available at the device level. In general, analyzing sensormeasurements between devices 14 over time may be used to dynamicallygroup the devices 14, which may provide functional and logical groups ofdevices 14 without user input. However, in some situations users may notwish to automatically implement such grouping. In these situations, asuggestion to group a number of devices 14 may be provided instead ofautomatically grouping the devices 14. Only if a user providesconfirmation will such a group be formed. Since the distributed lightingnetwork 10 allows for communication with remote devices 16, suggestedgroupings of devices may be provided to a user, for example, via acomputer, a smart phone, or the like.

One notable pattern that often indicates that devices 14 should begrouped together is based on a correlation in the running average of asensor measurement or sensor measurements of neighboring devices 14, asshown in Equation (1):

|RAS_(D1)−RAS_(D2) |>GR _(THSH)

where RAS_(D1) is the running average of a sensor measurement for afirst device 14, RAS_(D2) is the running average of a sensor measurementfor a second device 14, and GR_(THSH) is a grouping threshold. A runningaverage of a sensor measurement may be maintained by each device 14according to well-known formulae. In some embodiments, however, alightweight “running average” may be maintained to save processing powerand memory storage in each device 14. A lightweight running average maybe obtained according to Equation (2):

LRA=αSM_(CURR)+βLRA_(PREV)

where LRA is the lightweight running average, SM_(CURR) is a currentsensor measurement, LRA_(PREV) is a previously calculated lightweightrunning average, α is a first blending factor, and β is a secondblending factor. The blending factors may be predetermined byexperimentation in some embodiments, or may be adaptive. Using thelightweight running average described above may save memory andprocessing resources when compared to computing a full running average.In situations where memory and processing power are limited, this may behighly advantageous.

By way of example, neighboring devices 14 (which may be determined bythe link table discussed above with respect to FIG. 12) whose runningaverage of detected occupancy events are relatively close to one anotherindicate that they are in an area that is often used together, and thuscan be grouped. As discussed herein, an occupancy event occurs when ahuman enters or leaves a field of view of a sensor in a device 14.Detecting such events may be important, for example, so that a lightingfixture or group of lighting fixtures can adjust a light output levelthereof as light is required or desired in a particular space. Further,occupancy events may provide useful information about how a particularspace is currently or historically used, and thus may provide usefulinformation for characterizing a space. Occupancy events are generallydetected by a PIR sensor and/or image sensor, however, any suitablemeans for detecting an occupancy event may be used without departingfrom the principles of the present disclosure.

As another example, neighboring devices 14 whose running average ofambient light levels are similar may also be grouped. This may beespecially useful in light emitting devices configured to use “daylightharvesting,” such as current SmartCast™ lighting fixtures manufacturedby Cree, Inc. of Durham, N.C. Details of daylight harvesting arediscussed in U.S. patent application Ser. No. 14/681,846, the disclosureof which is hereby incorporated by reference in its entirety. In short,daylight harvesting involves changing the amount of light provided by alighting fixture 14A based on detected ambient light levels in the spacesuch that a task surface is illuminated at substantially the samebrightness throughout the day (even as the amount of light provided, forexample, through a window, changes). In some cases, when differentlighting fixtures 14A detect and act upon ambient light levelsindividually, differences in the light output of neighboring or nearbylighting fixtures 14A can be quite different, creating a visualdisruption. Using the principles described above, devices 14 withsimilar ambient light levels could be grouped. These grouped devices 14may be configured such that lighting fixtures 14A in the group providethe same light intensity, which may prevent uneven gradients of lightbetween lighting fixtures 14A due to manufacturing tolerances, slightchanges in the detected ambient light level between devices 14, and thelike.

The link table information shown in FIG. 12 may be useful not only fornetwork formation and grouping, but may be used to implement additionalfunctionality in the distributed lighting network 10. One such featureis referred to herein as “fluid occupancy,” the basic premise of whichis illustrated in FIGS. 16A through 16C. As shown in FIGS. 16A through16C, a single device 14 in a group of devices 14 may detect an occupancyevent. The device 14 that detects the occupancy event is referred to asthe “originating device” and is illustrated with a cross-hatch pattern.In response to the detection of the occupancy event, the originatingdevice 14 will begin providing light if it is capable of doing so (e.g.,if it is a lighting fixture 14A), or will simply notify other devices 14in the group if it is not capable of doing so. Neighboring lightingfixtures 14A of the originating device 14 will similarly turn on,forming a “bubble” of light around the originating device 14. Theseneighboring illuminated lighting fixtures 14A are illustrated with ahatch pattern. The number of neighboring lighting fixtures 14A that turnon in response to the detection of an occupancy event by the originatingdevice 14 may be adjusted. For example, only direct neighbors to theoriginating device 14 may turn on, neighbors separated from theoriginating device 14 by one other device 14 may turn on as well, orneighbors separated from the originating device 14 by up to n otherdevices 14 may turn on as well. The number of devices 14 located betweentwo devices 14 may be readily determined using the link table discussedabove with respect to FIG. 12. As shown in FIGS. 16A through 16C, as anoccupancy event is detected by a different device 14 (e.g., as anindividual moves closer to another device 14), that device 14 thenbecomes the originating device 14, and the neighboring lighting fixtures14A turn on. The result is a “bubble” of light that is capable offollowing an individual as they move throughout a space. This light“bubble” may provide security by allowing an individual to see aroundthem while simultaneously saving energy by preventing over-lighting aspace. Notably, the light output of each lighting fixture 14Asurrounding the originating device 14 may diminish in proportion to thedistance of the lighting fixture 14A from the originating device 14. Forexample, lighting fixtures 14A that are directly adjacent to theoriginating device 14 may provide maximum light output, lightingfixtures 14A that are one device 14 removed from the originating device14 may provide 50% light output, etc.

FIG. 17 is a call flow diagram illustrating a process for implementingthe fluid occupancy functionality discussed above. First, an originatingdevice 14 detects an occupancy event (step 500). The originating device14 then indicates that an occupancy event has been detected to one ormore lighting fixtures 14A in the group or lighting network 12 (step502). Each lighting fixture 14A that is notified of the occupancy eventchecks if it is within n devices 14 of the originating device 14 (step504), where n is the preferred threshold for surrounding illumination.This is determined, for example, by referencing the link table discussedabove in FIG. 12. If necessary, each lighting fixture 14A then adjuststhe light output thereof (step 506). Each lighting fixture 14A may alsoinitiate an occupancy timeout in response to the indicating of anoccupancy event by the originating device 14. This occupancy timeout maybe counted against a real-time clock. On expiration of the occupancytimeout, the lighting fixture 14A may reset the light output thereof toa previously stored setting, or may turn off altogether. Notably, theoccupancy timeout in each lighting fixture 14A may executeindependently. In some cases, different lighting fixtures 14A mayreceive notifications from multiple neighboring devices 14 that anoccupancy event has occurred. In the case where a different light outputlevel is used based on the distance of the lighting fixture 14A from theoriginating device, there may be a conflict regarding which light outputlevel a lighting fixture 14A should provide. Generally, this may beresolved by using the highest light output level, the lowest lightoutput level, an average of the highest light output level and thelowest light output level, or any other suitable value.

While the above example is primarily discussed in terms of occupancyevents, any number of different sensor measurements may be used toinitiate a similar process. For example, the detection of an object(e.g., via an image sensor) may cause a similar illumination pattern tothat discussed above. For example, a similar “bubble” of light mayfollow cars around a parking garage, which may forego the need forilluminating the entire garage, thus saving significant amounts ofenergy.

The fluid occupancy process discussed above may be used primarily withingroups of devices 14. However, in some embodiments, devices 14 outsideof a group in which an occupancy event is detected may also beilluminated. For example, the lights in neighboring groups mayparticipate in the fluid occupancy process as occupancy events aredetected near a border of the group in which the occupancy event isdetected and the neighboring group. For example, as an individual movesthrough a hallway, lighting fixtures 14A in the hallway may illuminatean area surrounding the individual, and lighting fixtures 14A in roomslocated off the hallway may illuminate the rooms as the individual walksby. This may provide the individual a greater sense of security byallowing the individual to view the inside of the rooms. In someembodiments, the lighting fixtures 14A in neighboring groups may providea lower light level than the lighting fixtures 14A in a group in whichan occupancy event was detected.

In some embodiments, the devices 14 may attempt to predict the path ofmovement of an individual or object, and may adjust the output of one ormore lighting fixtures 14A to illuminate this predicted path. Asoccupancy events are detected by devices 14 in a group, other devices 14in the group may receive notifications of these occupancy events. Afirst occupancy event may occur n devices 14 away, a second occupancyevent may occur n−1 devices away, and so on, until it may be predictedthat a particular device 14 will be next to detect an occupancy event.Such prediction may become significantly easier when image sensors areinvolved, as motion vectors may be computed for objects using data fromthe image sensors. The predicted path may then be illuminated.

In addition to the above, the link table may be used to illuminate adesired path to a particular location within a space. Such a feature maybe used, for example, to illuminate a path towards exits during anemergency. In such an embodiment, a device 14 at or near a desired pointin the space, referred to as a “key” device 14, may be designated, andthe neighboring lighting fixtures 14A of the key device 14 maysequentially turn on in sequence to their neighbor ranking to the keydevice 14. This results in a pattern of light that directs attentiontowards the designated feature, and thus may be used to guide anindividual towards the designated feature. FIGS. 18A through 18Dillustrate the basic premise of this feature. As shown, a key device 14is illustrated with a cross-hatch pattern. Lighting fixtures 14A at amaximum neighbor rank away from the key device (two in the presentembodiment) are illuminated together in FIG. 18A, followed by lightingfixtures 14A that of the next lowest neighbor ranking in FIG. 18B (onein the present embodiment), and finally be those devices 14 with thelowest neighbor ranking (zero in the present embodiment) in FIG. 18C. Ifthe key device 14 is capable of providing a light output, it may then doso alone as shown in FIG. 18D. It is apparent that such a pattern oflight will direct an observer's attention towards the key device 14,which may be useful in any number of different scenarios.

As discussed above, it may thus be desirable to know which devices 14are near an entrance and/or exit to a space. In order to make such adetermination, occupancy events may be analyzed over time. In a group ofdevices 14, the first device 14 to see an occupancy event will generallybe the closest to an entrance, while the last device 14 to see anoccupancy event will generally be closest to an exit. While this may notbe true every time due to false detections, misdetections, timing, etc.,a long running average of the first and last devices 14 in a group thatobserve an occupancy event are extremely likely to be the nearest to anentrance and exit of the group, respectively. This information may beused to designate entrance and exit devices 14, which may providespecial functionality as discussed below.

FIG. 19 is a flow diagram illustrating a method for detecting a device14 near an entrance and/or exit to a space according to one embodimentof the present disclosure. One or more occupancy events detected by thedevices 14 in a group are first provided (step 600). Each occupancyevent is then analyzed to determine if it was the first occupancy eventdetected after a previous occupancy timeout (step 602). When anoccupancy event is detected by a device 14, an occupancy timeout isinitiated. If an additional occupancy event is not detected before theoccupancy timeout expires, it is determined that an individual is nolonger present in the space. One or more lighting fixtures 14A in thegroup may then adjust the light output provided therefrom. If anoccupancy event was the first to occur after a previous occupancytimeout, an entrance device counter associated with the device 14 thatdetected the occupancy event is incremented (step 604). The entrancedevice counter is then compared to a threshold value (step 606). Thisthreshold value may be fixed, or may be a relative value that isdetermined with respect to the entrance device counter of each otherdevice 14 in the group. If the entrance device counter is above thethreshold value, the device 14 is designated as an entrance device (step608), and the process returns to step 610. If the entrance devicecounter is not above the threshold value, the process returns to step610. If the occupancy event was not the first to occur after a previousoccupancy timeout, the process skips step 604, step 606, and step 608,proceeding directly to step 610. Each occupancy event is then analyzedto determine if it was the last occupancy event detected before anoccupancy timeout (step 610). If an occupancy event was the last beforean occupancy timeout, an exit device counter for the device thatdetected the occupancy event is incremented (step 612). The exit devicecounter is then compared to a threshold value (step 614). As discussedabove, the threshold value may be fixed, or may be relative to a valuethat is determined with respect to the exit device counter for eachother device 14 in the group. If the exit device counter is not abovethe threshold value, the process returns to step 602. If the exit devicecounter is above the threshold value, the device 14 is designated as anexit device (step 616).

In one embodiment, one or more lighting fixtures 14A may indicate adesired placement of a border router 14D in a space. Accordingly, FIG.20 is a flow diagram illustrating a method for indicating a preferredplacement of a border router 14D in a space according to one embodimentof the present disclosure. First, a desired position for a border router14D in a space is determined by the devices 14 in a lighting network 12(step 700). Such a desired position may be determined, for example, byexamining the number of network collisions throughout the lightingnetwork 12 and finding a spot where the collisions are lowest, byexamining the total network traffic throughout the lighting network 12and finding a spot where the traffic is the lowest, examining thereceived signal strength of each device 14 in the lighting network 12and determining where there is the least amount of external interferencetherein, or by examining any other network performance or otherparameter that is detectable by the devices 14 in the network. Thedesired position of the border router 14D is then indicated by one ormore lighting fixtures 14 in the network (step 702). This can be donesimilar to the process discussed above by directing an individual'sattention towards the desired position, or may be indicated by a singlelighting fixture 14A, or in any other desired fashion. By detecting andindicating a desired position for a border router 14D, the performanceof the border router 14D may be improved by optimizing the communicationbetween one or more devices in the network and the border router 14D.

In addition to the above, the link table discussed above in FIG. 12 maybe used to improve an ambient light sensor calibration process ofdevices 14 in a lighting network 12. Accordingly, FIG. 21 is a flowdiagram illustrating a method for calibrating the ambient light sensorsof one or more devices 14 in a lighting network 12. Upon initiation ofan ambient light sensor calibration process at a particular device 14,which may be particularly chosen by a user, chosen at random, or chosenin any desired fashion, the light output of neighboring lightingfixtures 14A to the device is set to zero (step 800). This is necessaryto avoid contaminating ambient light readings with the light output ofthe neighboring lighting fixtures 14A. In some embodiments, any lightingfixture 14A from which light was detected by the device 14 in theautomatic grouping process discussed above may set its light output tozero for proper calibration to occur. Next the ambient light sensor(s)of the device 14 are calibrated (step 802). The light output of theneighboring lighting fixtures 14A is then restored to its previous level(step 804). Notably, this ambient light sensor calibration process maysignificantly improve over previous approaches, which adjusted the lightoutput of every lighting fixture 14A in a space to zero in order tocalibrate the ambient light sensors of the devices 14 therein. Whilewaiting to confirm that each lighting fixture 14A had properly adjustedthe light output thereof, the space would be unlit, and therefore may beunusable for a period of time. The above process allows the majority ofthe space to remain usable during such a calibration period.

Previously, devices 14 in a wireless lighting network 12A communicatedwith one another using a single wireless communications channel, whichmay have been chosen at random or by a user. This often resulted insub-optimal wireless communication between the devices 14. In somecases, the wireless communications channel chosen for the devices 14 wasbased on network conditions, however, the network conditions for onedevice 14 or group of devices 14 may vary significantly throughout aspace. For example, one device 14 or group of devices 14 may be locatednear a large source of radio frequency (RF) noise such as an RF deviceoperating in a similar frequency spectrum, or may be located near anobstacle to wireless signals such as a metal structure. Accordingly,FIG. 22 is a call-flow diagram illustrating a method for optimizing awireless communications channel for communication between devices 14 ina wireless lighting network 12A according to one embodiment of thepresent disclosure.

First, each device 14 determines an optimal communications channel (step900). Each device 14 may make this determination, for example, based ona local analysis of network traffic, network collisions, or any othernetwork performance metric that is measurable by each device 14. Theoptimal channel determined by each device 14 is then shared with eachother device 14 in the wireless lighting network 12A (step 902). Eachdevice 14 may store the optimal channel determined by each other device14 (step 904). Each device 14 may further determine which sharedcommunications channel should be used in the wireless lighting network12A or a subset thereof, such as a group (step 906). For example, if amajority of devices 14 in the wireless lighting network 12A determinedthe same optimal communications channel, this channel may be used forcommunication within the wireless lighting network 12A. Similarly, ifthe majority of devices 14 in a group determined the same optimalcommunications channel, this channel may be used for communicationwithin the group. Notably, each device 14 may communicate on a differentcommunications channel with each other device 14 based on the optimalcommunications information that was previously shared amongst thedevices 14. For example, a device 14 may look-up the optimalcommunications channel for another device 14 before communicationtherewith, and use this optimal communications channel. This may occurat any level of granularity, such as on a device 14 level, on a grouplevel, or on a network level. The determined shared communicationschannel may then be shared between the devices 14 (step 908) so that itcan be used as discussed above.

FIG. 23 is a call-flow diagram illustrating a method for optimizing awireless communications channel for communication between devices 14 ina wireless lighting network 12A according to an additional embodiment ofthe present disclosure. First, the devices 14 in a network providenetwork information about the network to a border router 14D (step1000). The network information may include any network parameters thatare measurable by the devices 14 as discussed above. The border router14D then determines an optimal communications channel for each device 14in the wireless lighting network 12A (step 1002). Further, the borderrouter 14D may determine the optimal shared communications channel forthe wireless lighting network 12A or any subset thereof such as thegroups in the wireless lighting network 12A (step 1004). The borderrouter 14D may then share these optimal communications channels andoptimal shared communications channel with each device 14 (step 1006).

The features described above allow for the formation of an improveddistributed lighting network 10. The distributed lighting network 10 isunique in that it provides intelligent devices 14 at fixed pointsthroughout a space. These devices 14 may be leveraged to introducesignificant new functionality into a space, and to provide valuableinsights about the space. As an infrastructure for lighting isubiquitous in most modern spaces, the distributed lighting network 10may be provided in a space without significant investment in newinfrastructure.

The sensors included in each device 14 in the distributed lightingnetwork 10 may provide a very large amount of information about thespace in which they are located. Data from these sensors may be utilizedto gain insights about the space that were previously unachievable, andthus add new and interesting features to the distributed lightingnetwork 10. This is due to the fact that these sensors may bedistributed throughout the space in a relatively fine-grained fashion,and are capable of communicating with one another and other remotedevices 16. As discussed above, the infrastructure afforded to lightingis especially suited for this task.

In particular, providing an image sensor in each device 14 or a subsetof devices 14 in the distributed lighting network 10 may provideextensive insights about a space. First and foremost, however, an imagesensor may be used to perform the function of several other sensors,such as a PIR occupancy sensor and an ambient light sensor. Certainaspects of detecting occupancy and ambient light using an image sensorare discussed in copending U.S. patent application Ser. No. 14/928,592,the contents of which are hereby incorporated by reference in theirentirety.

Detecting occupancy events using an image sensor may prove especiallychallenging in some circumstances. Simply looking for differencesbetween pixel values in frames obtained from an image sensor isinadequate, as there are many sources of noise that may cause falseoccupancy event detections. For example, low-level noise such as darkcurrent, thermal noise, and analog-to-digital conversion noise may bemisinterpreted as motion and thus trigger an occupancy event in somecircumstances. Further, modulation of light sources (e.g., fluorescentlights, pulse-width modulated solid-state light sources, etc.) orsources of repetitive motion such as the rotation of a fan or the swayof a tree branch in a nearby window may be misinterpreted as anoccupancy event. Changes in ambient light, for example, due to cloudcoverage or a change in light output of one or more lighting fixturesmay also be misinterpreted as an occupancy event. For outdoor fixtures,rain, snow, sleet, insects, and animals traversing a field of view of animage sensor may be misinterpreted as an occupancy event. Accordingly,FIGS. 24A and 24B illustrate a flow diagram illustrating a method fordetecting occupancy events using an image sensor according to oneembodiment of the present disclosure.

First, a frame counter (i) is set (step 1100). The frame indicated bythe frame counter is then obtained (step 1102). For example, the framemay be obtained by requesting it from an image sensor, or by viewing theframe as it is stored in memory. Next, a zone counter (k) is set (step1104). The zone indicated by the zone counter in the frame indicated bythe frame counter is then obtained (step 1106). The zone may includepixel values for each pixel within the zone. An average (e.g., a runningaverage) of the pixel change value for each pixel in the zone RAVGPV_(Z)is then updated (step 1108). As discussed above, the pixel value (andthus the pixel change value) may be a brightness value, a luma value, acolor value, raw pixel data (i.e., pixel data that has not beenprocessed e.g., via a demosaic process, referred to herein as a rawvalue), or the like. An average of the pixel change value for the zoneAVGCPV_(Z) may be calculated according to Equation (3):

${AVGCPV}_{Z} = \frac{{CPV_{P1}} + {CPV_{{P2}\mspace{14mu}}\text{…}} + {CPV}_{PN}}{NP_{Z}}$

where AVGCPV_(Z) is the average of the pixel change value for the zone,CPV_(PX) is the pixel change value for a particular pixel within thezone (calculated as described below), and NP_(Z) is the number of pixelsin the zone. The running average of the pixel change value for the zoneRAVGCPV_(Z) may then be calculated according to Equation (4):

RAVGCPV_(Z)=αAVGCPV_(ZCURR)+βRAVGCPV_(ZPREV)

where RAVGCPV_(Z) is the running average of the pixel change value forthe pixels in the zone, RAVGCPV_(ZCURR) is the current average of thepixel change value for the pixels in the zone, RAVGCPV_(ZPREV) is thepreviously calculated running average of the pixel change value for thepixels in the zone, α is a first blending factor, and β is a secondblending factor. The updated running average of the pixel change valuefor the pixels in the zone RAVGCPV_(Z) is then stored (step 1110).

Next, a pixel counter (j) is set (step 1112). The pixel indicated by thepixel counter in the zone indicated by the zone counter in the frameindicated by the frame counter is then obtained (step 1114). A runningaverage of the pixel value for the pixel RAVGPV_(P) is then updated(step 1116). A running average of the pixel value for the pixelRAVGPV_(P) may be calculated according to Equation (5):

RAVGPV_(P)=αPV_(P)+βRAVGPV_(PPREV)

where RAVGPV_(P) is the running average of the pixel value for thepixel, PV_(P) is the pixel value of the pixel, RAVGPV_(PPREV) is thepreviously calculated running average of the pixel value the pixel, α isa first blending factor, and β is a second blending factor. The runningaverage of the pixel value RAVGPV_(P) is then stored (step 1118). Anabsolute difference between the pixel value of the pixel PV_(P) and therunning average of the pixel value of the pixel RAVGPV_(P) is thencalculated (step 1120), the result of which is the pixel change value.In some embodiments, this may be calculated based on the previouslycalculated running average of the pixel value of the pixelRAVGPV_(PPREV) instead of the updated running average of the pixel valueRAVGPV_(P). This pixel change value is then normalized by dividing thepixel change value by the running average pixel change value for thezone RAVGCPV_(Z), and compared to a threshold (step 1122). Thisessentially provides a Boolean indicator for whether a change in a pixelvalue is reliably significant and meaningful. If the difference betweenthe pixel value of the pixel PV_(P) and the running average pixel valueof the pixel RAVGPV_(P) divided by the running average of the pixelchange value for the zone RAVGCPV_(Z) is greater than a threshold, apixel change counter is incremented for the zone (step 1124). Adetermination is then made whether the pixel change counter is largerthan half of the number of pixels in the zone (step 1126), indicatingthat at least half of the pixels in the zone experienced a significantchange. Notably, any fraction of the pixels in the zone may be usedwithout departing from the principles of the present disclosure (e.g.,the determination may be whether the pixel change counter is greaterthan at least a quarter of the pixels in the zone, an eighth of thepixels in zone, or any other fractional value of the pixels in thezone). If the pixel change counter is larger than half the number ofpixels in the zone, a zone change flag is raised (step 1128), indicatingthat a reliably significant change was detected in the zone. Notably,each zone may be sized to detect an object at a desired size. Forexample, the size of the zone may be around two times the size of anindividual in the field of view of the camera sensor so that half of thepixels should indicate the detection of an object that is about thatsize. The zone change flag may be an indication that the pixel valuesfor the pixels in the zone may need to be updated by transmission to aremote device as discussed above. A determination is then made whetherthe number of adjacent zone change flags for the frame is above athreshold value (step 1130). If a number of adjacent zone change flagsis above a threshold value, this indicates a change in pixel values overa large portion of the frame, and is assumed to be a false alarm.Accordingly, the frame is discarded (step 1132), the frame counter isincremented (step 1134), and the process returns to step 1102. In lieuof step 1430, in some embodiments, if the determination made in step1122 is positive for a number of pixels in the frame over a thresholdvalue, the frame is similarly labeled a false detection and discarded.

If the number of adjacent zone change flags in the frame is not abovethe threshold, the zone counter is incremented (step 1136). Adetermination is then made whether the zone change counter is greaterthan the number of zones in the frame (step 1138). If the zone counteris greater than the number of zones in the frame, a determination ismade if the zone change flag(s) in a previous frame (i−1) are within nzones of the zone change flag(s) in the current frame (i) (step 1140).This indicates movement within the frame, where n is a value chosenbased on the framerate of the image sensor such that the detectedmovement is occurring with a velocity threshold for a desired object(e.g., the average moving speed of a human, slow-moving vehicle, or thelike). Generally, the zone change flag(s) between frames should move atleast one zone, if not more to indicate movement between frames and thusavoid false detections. Zone change flag(s) moving greater than n zonesare moving too fast to be an object that the image sensor is interestedin detecting and thus are ignored. If the zone change flag(s) in aprevious frame are within n zones of the zone change flag(s) in thecurrent frame, an occupancy event is detected (step 1142), the framecounter is incremented (step 1134), and the process returns to step1102. If the zone change flag(s) in a previous frame are not within nzones of the zone change flag(s) in the current frame, the frame counteris incremented (step 1134), and the process returns to step 1102 withoutindicating an occupancy event.

If the pixel change counter is not larger than half the number of pixelsin the zone, the pixel counter is incremented (step 1144). Adetermination is then made whether the pixel counter is greater than thenumber of pixels in the zone (step 1146). If the pixel counter is notgreater than the number of pixels in the zone, the process returns tostep 1214. If the pixel counter is greater than the number of pixels inthe zone, the process returns to step 1136.

The above process has several advantages over conventional imageprocessing techniques directed towards object detection. First, therunning averages calculated above may be done so by using the blendingfactors (rather than conventional running average techniques), which maysave processing power and memory resources. Second, using the runningaverage of the change of luma in a zone, rather than at the pixel levelfurther saves memory resources by preventing the storage of a runningchange in luma value for each pixel. In general, the above is alightweight image processing technique that may be used to detectoccupancy events using an image sensor. The image processing techniquemay be capable of implementation on each individual device 14 includingan image sensor, such that an image sensor may provide occupancy eventdetection in each device 14. Due to the fact that an image sensor mayfurther provide the functionality of other sensors as well, such asambient light sensors, using the image sensor in place of these othersensors may save space and cost in the devices 14.

While PIR sensors and image sensors may be used alone to detectoccupancy events, additional sensor data may be used either alone or incombination with the above to further increase the accuracy ofdetection. For example, changes in atmospheric pressure may correspondwith an individual entering a space, and thus may be used either aloneor in combination with data from a PIR or image sensor to detect anoccupancy event. This may be especially true in the case of a room witha door. The pressure in such a room will significantly change upon openor close of said door, and thus detecting such a change using anatmospheric pressure sensor may be a simple way to detect when someonehas entered or left the room (corresponding with an occupancy event).Further, vibration and/or motion detected from an accelerometer in adevice 14 may be further indicative of an occupancy event, and thus maybe used alone or in combination with data from a PIR or image sensor todetect an occupancy event. Finally, sound detected from a microphone maybe indicative of an occupancy event, and may be used alone or incombination with data from a PIR and/or image sensor to detect anoccupancy event. All of the data from the atmospheric pressure sensors,the vibration and/or motion sensors, and the microphones may be usedaccording to the principles described above in order to reducebackground noise therein. That is, changes in a long-running average ofthese sensor measurements may be much more indicative of an event thaninstantaneous changes therein, and thus the measurements may be examinedin this manner in order to detect one or more occupancy events. Changesin sound levels using the microphone may be especially useful, asdifferent changes may correlate with different “degrees” of occupancy.That is, using measurements from a microphone either alone or incombination with data from a PIR and/or image sensor may allow for arough estimate of how many individuals are occupying and/or using aspace, which may provide additional insights about the space.

In one embodiment, an accelerometer is provided near an image sensor ina device 14. Data from the accelerometer may then be used to determineif the device 14 is moving. Such movement may be likely to indicate, forexample, that distortion will occur in the output of the image sensor(e.g., from shaking, swaying, or the like). In order to avoid falseoccupancy detections due to such movement, the data from theaccelerometer may be used in conjunction with data from the imagesensor, where occupancy events detected by the image sensor are ignoredor further processed with the accelerometer indicates movement above acertain threshold.

As discussed above, certain distractors such as precipitation, snow,insects, and animals may cause false detections in outdoor devices 14.Often, these distractors are much more likely to create a falseoccupancy event detection when they are detected very near the imagesensor. As insects and animals are often attracted to light, this mayoccur frequently. Accordingly, in one embodiment a lens associated withan image sensor on a device 14 is configured with a focal length that istailored to a desired detection length from the image sensor. Forexample, the minimum focal length of the lens may be at least 1 foot, atleast 3 feet, at least 9 feet, and the like. Creating such a minimumfocal length causes objects that are near to the image sensor to remainblurry, and thus reduces their detection by the image sensor. This mayavoid false detection of occupancy events due to these distractors. Insome cases, an integration time associated with the image sensor mayalso be adjusted to “filter” out fast-moving distractors such asprecipitation, snow, insects, and animals. Often, these distractorsappear to be moving very quickly due to their proximity to the imagesensor and velocity. By increasing an integration time of the imagesensor to capture objects moving within a desired range of velocities(e.g., human walking or running speeds, the speed of slow-movingvehicles, etc.), faster moving objects such as the above-mentioneddistractors may essentially be ignored by the image sensor, therebyavoiding false detection of occupancy events.

The foregoing process for detecting an occupancy event with an imagesensor is merely illustrative, and not exhaustive. There are manydifferent ways to detect occupancy events using an image sensor, all ofwhich are contemplated herein. One problem with detecting occupancyevents with an image sensor is that there is a minimum required level oflight for doing so. That is, at light levels below a certain threshold,the signal-to-noise ratio (SNR) of an image sensor becomes too high todetect occupancy events. Accordingly, FIG. 25 illustrates a method foradjusting the light output of a lighting fixture 14A to maintain anecessary amount of light for detecting occupancy events using an imagesensor. Such adjustment may be done with respect to an image sensor onthe lighting fixture 14A itself, or with respect to an image sensor onany neighboring device(s) 14.

First, an occupancy timeout occurs (step 1200). As discussed above,after an occupancy event is detected, an occupancy timeout is initiated.As additional occupancy events are detected by a device 14 or within agroup, this occupancy timeout is re-initiated such that the occupancytimeout starts over. When occupancy events are not detected for a periodof time, the occupancy timeout occurs, indicating that the space is nolonger occupied. The light output of the lighting fixture 14A is thenset to a predetermined minimum level (step 1202). This predeterminedminimum level may be set up by a user or pre-programmed into thelighting fixture 14A. The goal of the predetermined minimum level is toprovide only the necessary amount of light so that one or more nearbyimage sensors may detect occupancy events. However, this light level maybe different for different image sensors, environmental conditions, andthe like. Accordingly, a determination is then made regarding whetherthe SNR of any nearby image sensors is above a threshold value (step1204). If the SNR of the image sensors is above the threshold value, thelight output of the lighting fixture 14A is decreased (step 1206) andthe process is returned to step 1204. If the SNR of the image sensor isbelow the threshold value, the light output of the lighting fixture isincreased (step 1208), and the process again returns to step 1204. Inthis way, the light output of the lighting fixture 14A is dynamicallyadjusted such that nearby image sensors are capable of detectingoccupancy while avoiding over-lighting a space.

The above process may be conducted on each lighting fixture 14A in agroup, in which case the lighting fixtures 14A may cooperate to ensurethat the light output levels thereof are substantially uniform. Ingeneral, however, such minimum lighting only needs to be done bylighting fixtures 14A that illuminate the area near one or moreentrances to a space. This is because it is known that an individualwill have to pass through an entrance to initiate occupancy at anydevice 14. Accordingly, the foregoing minimum dimming may only be doneon those lighting fixtures 14A that illuminate an area near an entranceto a space in order to save energy and avoid over-lighting the spacewhen it is not in use.

Generally, the sensitivity of image sensors is such that the minimumlight level discussed above will be very low. Such light levels may notbe achievable by conventional power converter circuitry used for solidstate lighting devices, which generally provide a pulse-width modulatedcurrent to a string or strings of LEDs as discussed above. As thecurrent required by a load becomes small, the timing between currentpulses in a pulse-width modulated signal becomes very small, requiring aswitching power converter that is capable of very fast switching speeds.Such a switching power converter may be impractical due to costconstraints, or impossible altogether. Accordingly, FIG. 26 illustratespower converter circuitry 26 for a lighting fixture 14A according to oneembodiment of the present disclosure. The power converter circuitry 26includes low light output power converter circuitry 80 and standardlight output power converter circuitry 82. The low light output powerconverter circuitry 80 and the standard light output power convertercircuitry 82 may each be coupled to an input voltage (V_(IN)), andcoupled together at a number of outputs, each of which are configured topower a different LED string. The low light output power convertercircuitry 80 may be configured to provide a linear output signal, whilethe standard light output power converter circuitry 82 may be configuredto provide a pulse-width modulated output signal. Accordingly, the lowlight output power converter circuitry 80 may be a linear regulator,while the standard light output power converter circuitry 82 may be aswitching power converter such as a buck converter, a boost converter, abuck-boost converter, or the like. Notably, the low light output powerconverter circuitry 80 may be less efficient than the standard lightoutput power converter circuitry 82 at standard light levels, however,the difference in efficiency may be negligible at the low light levelsthat the low light output power converter circuitry 80 is used for.Further details of an ultra-low dimming lighting fixture may be found inco-filed U.S. Pat. No. 9,730,289 filed Feb. 8, 2016 and titled “SolidState Light Fixtures Having Ultra-Low Dimming Capabilities And RelatedDriver Circuits And Methods”, the disclosure of which is herebyincorporated by reference in its entirety.

Another problem that may arise in detecting occupancy events using animage sensor occurs when a neighboring lighting fixture 14A to a device14 abruptly adjusts the light output thereof. Neighboring devices 14 tothe lighting fixture 14A may falsely detect the changing light output asan occupancy event in some circumstances, which may result in a controlloop in which the device 14 prevents the lighting fixture 14A fromadjusting the light output thereof as desired. This is a particularproblem when a lighting fixture 14A experiences an occupancy timeoutevent and thus attempts to reduce the light output thereof, as nearbydevices 14 may then detect this reduction in light output as anoccupancy event, causing the lighting fixture 14A to increase the lightoutput thereof. One way to compensate for this is for lighting fixtures14A to pre-announce when the light output thereof is going to change, sothat nearby devices 14 can ignore said changes. For example, nearbydevices 14 may ignore occupancy events detected by an image sensorassociated therewith for a period of time after such announcement.However, this may be undesirable in some circumstances, as these devices14 may then fail to detect the occurrence of an actual occupancy event.Accordingly, in some embodiments nearby devices 14 may ignore only aportion of a field of view of an image sensor associated therewith, andspecifically that portion that is affected by the light output of theneighboring lighting fixture 14A. For example, a frame of an image froman image sensor may be divided into a number of zones, and only thosezones that are affected by the neighboring lighting fixture 14A (whichmay be determined, for example, during the automatic grouping processdiscussed above) may be ignored. However, even this may result in missedoccupancy event detections.

Accordingly, in some embodiments the amount of light change from theneighboring lighting fixture 14A, which may be predetermined during theautomatic grouping process or determined based on communication with thelighting fixture 14A may be taken into account and ignored, while otherchanges detected by the image sensor according to the processesdescribed above may continue to function. In other words, the automaticgrouping process discussed above may indicate that a neighboringlighting fixture 14A is detected at a certain intensity by the device14. The device 14 may then ignore changes in light output detected bythe image sensor associated therewith within this range. This allows forthe continuing detection of occupancy events while failing to falselydetect occupancy events based on the changing light output ofneighboring lighting fixtures 14A.

Yet another, simpler way to avoid the above mentioned problems is to dimthe light output of neighboring lighting fixtures 14A slowly upon theoccurrence of an occupancy timeout. If done slowly enough, this preventsnearby devices 14 from falsely interpreting the changing light outputfrom nearby lighting fixtures 14A as an occupancy event and thus avoidsthe control loop problems discussed above. Generally, it is not criticalto instantly reduce the light output in a space on the occurrence of anoccupancy timeout. Accordingly, the above method is a simple buteffective way to avoid entering undesirable control loops betweenneighboring devices 14 using image sensors to detect occupancy events.

It may be desirable for the image sensor to be capable of detecting acommissioning tool used in the distributed lighting network 10 tocommunicate with the various devices 14. Details regarding theinitiation of communication between a device 14 and a commissioning toolare discussed in detail in U.S. patent application Ser. No. 13/782,022,the disclosure of which is hereby incorporated by reference in itsentirety. In short, the commissioning tool includes a light emittingdevice of a certain color, which must be detected by a device 14 toensure that the commissioning tool is attempting to communicatespecifically with that device 14. If the light emitting device were notpresent on the commissioning tool, messages sent, for example, via awireless signal, could be received and acted upon by any number ofnearby devices 14. Previously, light from the commissioning tool wasdetected by an ambient light sensor in a device 14. However, asdiscussed above it may be desirable to replace the functionality of adedicated ambient light sensor with an image sensor. Accordingly, FIG.27 is a flow diagram illustrating a method of detecting a commissioningtool using an image sensor according to one embodiment of the presentdisclosure.

Upon initiation of the detection process, which may be in response to awireless signal provided by the commissioning tool indicating that itwishes to communicate with a nearby device 14, the gain of the imagesensor is first zeroed for any undesired colors (step 1300).Specifically, the gain of the image sensor is zeroed for all colorsexcept the color of the light emitting device on the commissioning tool.If the commissioning tool is in the field of view of the image sensor,the resulting image will include a highly saturated area where the lightemitting device of the commissioning tool is located due to the gainzeroing. Accordingly, the integration time of the image sensor is thenadjusted such that the brightest object in the frame (which should bethe light emitting device of the commissioning tool) is below saturation(step 1302). The frame is then windowed to the bounds of the brightestobject, which, once again, is the light emitting device of thecommissioning tool (step 1304). This windowing allows the image sensorto reduce the amount of data that it needs to collect, and therefore mayenable the frame rate of the image sensor to be increased (step 1306).This is important, as the light provided by the commissioning tool maybe modulated at a particular frequency to prevent false detections ofother light emitting devices during this process. To assure that themodulation frequency of the light provided by the commissioning tool isdifferent from standard sources of interference, the light signal may bemodulated at a frequency above 60 Hz (e.g., 80 Hz). Many image sensorsare incapable of providing frame rates capable of detecting modulationat this frequency. The dynamic windowing around the light provided fromthe commissioning tool may remedy this, as the frame rate of the imagesensor is proportional to the area sampled thereby in many cases. Anumber of frames from the image sensor are then sampled (step 1308), andit is determined if the sampled frames are modulated at a desireddetection frequency (i.e., the modulation frequency of the lightprovided by the commissioning tool) (step 1310). This may be done, forexample, by looking for a beat frequency which is the difference of thesample frequency of the image sensor and the modulation frequency of thelight provided by the commissioning tool. If the modulation is detected,the device 14 will respond to the commissioning tool (step 1312). If themodulation is not detected, the device may cease searching for thecommissioning tool (step 1314).

While image sensors may be used to implement the functionalitypreviously served by other sensors, they may also be used to implementnew functionality in the distributed lighting network 10. One suchfunction is security, wherein the image sensors may be used not only todetect occupancy events and ambient light levels, but also to provideimages of a space to a central location for security purposes. In manywireless lighting networks 12A, such functionality may be problematic,as the mesh networks used by the devices 14 therein may not be suitedfor the transfer of high bandwidth data such as images and video.Certain compression techniques may be used to circumvent this effect,such as only sending images and/or video when something in the frame haschanged, using well-known video compression codecs such as MPEG-4 andH.264, or the like. However, in some situations even this may beinsufficient to overcome these shortcomings. Accordingly, one or more ofthe devices 14 in the network may communicate this image and/or videodata over a secondary communications means that is better suited forthese tasks. For example, one or more of the devices 14 may connect to aWiFi network or other high-speed wireless communications network inorder to provide images and/or video from image sensors in the devices14 to a desired destination.

While images and/or video of a space are useful when viewed separately,it may be more advantageous to provide a unified visual representationof a space in some cases. For example, images from multiple devices 14in the distributed lighting network 10 may be merged together at theirpoints of overlap to present a unified overhead view of the space. Thisimage may be very high resolution, as it combines the resolution of eachof its constituent images. Such an image and/or video stream may beviewed together and thus provide an excellent overview of what ishappening within the space at any given time.

FIG. 28 is a flow diagram describing a method for providing such amerged image. First, images from multiple image sensors are provided(step 2400). The images are then processed (step 1402). The processingmay include not only merging the images at their points of overlap, butalso de-warping, de-skewing, and otherwise compensating the images forany distortion therein. A merged image is then provided (step 1404). Adetermination is then made regarding whether a change has been detectedfrom any of the image sensors (step 1406). If a change has beendetected, new images are obtained from the image sensors (step 1408),and the process returns to step 1402 to process these images and providethe merged image once again. If no changes have been detected by theimage sensors, the merged image continues to be provided as in step1404. This prevents the unnecessary use of bandwidth in the network, asit only requires updated images when something in the space has changed.

In addition to the above, it may also be highly advantageous tocorrelate image data from one or more image sensors with geospatial dataobtained from one or more other sensors. Correlating image data withgeospatial data allows for a real-space representation of a space to beconstructed, which may be highly useful in many situations. Such aprocess may be referred to as georegistration of image data, and a flowchart describing the basics of such is shown in FIG. 29. First,geospatial data from one or more sensors and image data from one or moreimage sensors is provided (step 1500). The image data and the geospatialdata are then correlated (step 1502). Generally, if two points of imagedata (e.g., pixels or areas) can be correlated with two points ofgeospatial information (e.g., latitude and longitude, GPS coordinates,etc.), the image data can be considered georegistered and a real-spacerepresentation of the space can be generated. Next, image data may bepresented based on the correlation of image data and geospatial data(step 1504). This may involve presenting the image data such that it isproperly oriented, properly scaled, or the like. Further, the image datamay be displayed with geospatial information overlayed thereon (step1506), which may provide additional context to the image data. Furtherapplications of an image sensor in one or more devices 14 in thedistributed lighting network 10 are discussed below.

While georegistering image data may be important in some circumstances,it may be equally or more important to map and register the lightingfixtures 14A and other devices 14 in the distributed lighting network10, such that the relative or absolute locations of the lightingfixtures 14A and other devices 14 are known. Knowing the location of thelighting fixtures 14A and other devices 14 may be important, forexample, when displaying information collected by the lighting fixtures14A and other devices 14, as described in coassigned and copending U.S.patent application Ser. No. 14/826,892 and U.S. patent application Ser.No. 14/827,007, the contents of which are hereby incorporated byreference in their entirety. Accordingly, FIG. 30 is a flow diagramillustrating a process for mapping and registering lighting fixtures 14Aand other devices 14 in the distributed lighting network 10 according toone embodiment of the present disclosure. While the following steps arediscussed primarily with respect to lighting fixtures 14A, the sameconcepts may be applied to any of the devices 14 in the distributedlighting network 10 without departing from the principles describedherein. Further, the process described below may be carried out by anysuitable device 14 in the distributed lighting network 10. Since theprocess may be computationally intensive, a computer connected to thedistributed lighting network 10 may carry out the steps thereof.Alternatively, the processing may be distributed among the devices 14 inthe distributed lighting network 10 in some embodiments.

First, a number of distance measurements between a device 14 and eachone of a number of lighting fixtures 14A are obtained (step 1600). Thedistance between the device 14 and each one of the lighting fixtures 14Amay be determined by any suitable means. For example, RF ranging,wherein an RF signal is sent from the device 14 to a lighting fixture14A and sent back from the lighting fixture 14A to the device 14. Aphase of the returned RF signal may be used to determine a distancebetween the device 14 and the lighting fixture 14A. By traversing aspace including the lighting fixtures 14A, several distance measurementsbetween the device 14 and each lighting fixture 14A may be achieved. Asanother example, images captured from a camera on the device 14 may beused to determine a distance between the device 14 and a lightingfixture 14A. By identifying lighting fixtures 14A located in imagescaptured from a camera on the device 14 (a task that may easily beachieved using basic image processing techniques) and cross-referencingthe identified lighting fixtures 14A with odometry data (i.e.,accelerometer data, gyroscope data, and the like) from the device 14, adistance between the device 14 and the lighting fixtures 14A may beobtained as the device traverses a space including the lighting fixtures14A. As yet another example, a sound may be emitted by the device 14 andmeasured by the lighting fixtures 14A. The device 14 and the lightingfixtures 14A may then use this information to determine a distancebetween them. This may also be performed in reverse, such that one ofmore lighting fixtures 14A emits a sound that is measured by the device14. Such an approach is referred to herein as “acoustic ranging”. Thedevice 14 may be a commissioning tool for configuring the lightingfixtures 14A and devices 14 in the distributed lighting network 10, ormay be any suitable mobile device such as a mobile phone.

Next, the distance measurements obtained above are processed in order toassign coordinates to each one of the lighting fixtures 14A (step 1602),wherein the coordinates indicate the relative locations of the lightingfixtures 14A with respect to one another. In one embodiment, thedistance measurements are processed using simultaneous localization andmapping (SLAM) to obtain the coordinates for each one of the lightingfixtures 14A, however, any suitable processing techniques fortransforming distances between objects into a relative coordinate systemmay be used without departing from the principles of the presentdisclosure. In particular, a range-only SLAM approach may be used toobtain the coordinates for each one of the lighting fixtures 14A.Details of a SLAM approach to processing the distance measurements canbe found in “A Spectral Approach to Range-Only SLAM” by Byron Boots andGeoffrey J. Gordon, the contents of which are hereby incorporated byreference in their entirety.

Finally, registration of the coordinates for a subset of the lightingfixtures 14A is facilitated (step 1604). Registering the coordinates fora subset of the lighting fixtures 14A includes associating thecoordinates assigned to each one of the subset of the lighting fixtures14A with coordinates in a desired coordinate space. Facilitatingregistration may include providing a user interface or otherwiseenabling a user to enter information to register the coordinates.Registering the coordinates of a subset of the lighting fixtures 14Aallows the relative coordinates of the lighting fixtures 14A determinedabove to be translated into a real coordinate system such that theactual location of the lighting fixtures 14A is known. Depending on thecoordinates determined above, the size of the distributed lightingnetwork 10, and other variables such as the quality of the distancemeasurements, only a small number of lighting fixtures 14A may berequired in the subset. For example, registering the coordinates of twoor three of the lighting fixtures 14A may be sufficient to register theremaining lighting fixtures 14A, for example, via interpolating thecoordinates of the remaining lighting fixtures 14A with a Procrustessuperimposition, the details of which will be readily appreciated bythose skilled in the art. Registering the coordinates of the subset ofthe lighting fixtures 14A may be accomplished by manually allowing auser to associate the coordinates with a desired coordinate system. Forexample, a user interface may be provided, which facilitates a user inproviding an absolute location of one or more of the lighting fixtures14A, for example, on a floorplan of a building, as discussed in detailbelow.

FIG. 31 illustrates the process discussed above. As shown in FIG. 31,the device 14 obtains a number of distance measurements between itselfand a number of lighting fixtures 14A. As discussed above, thesedistance measurements may be based on RF ranging, imaging, odometry,acoustic ranging, or any other suitable techniques. Further, multipletechniques may be combined or “fused” to increase the accuracy ofdistance measurements. In general, the device 14 will move about a spacein which the lighting fixtures 14A are located, collecting distancemeasurements. Odometry data may track the relative movement of thedevice 14 throughout the space and be used to translate the variousmeasurements taken into distances between the device 14 and the lightingfixtures 14A. While the device 14 is shown as a mobile phone, anysuitable device 14 (e.g., a commissioning tool) may also be used withoutdeparting from the principles of the present disclosure. In embodimentsin which a mobile phone is used, the processing power thereof may besufficient to perform the foregoing process locally. In otherembodiments, the distance measurements may be provided to a computer orother device connected to the distributed lighting network 10, which inturn performs the processing.

In some embodiments wherein the device 14 is a mobile phone, the device14 may not include communications circuitry that is compatible with thelighting fixtures 14A in the distributed lighting network. For example,the device 14 may not include communications circuitry capable ofcommunicating via IEEE wireless communications standard 802.15.4.Accordingly, FIG. 32 shows a lighting network communications adapter 84that may be connected to the device 14 via a connector 86 in order toallow the device 14 to communicate directly with the lighting fixtures14A in the distributed lighting network 10. The lighting networkcommunications adapter 84 may be necessary to enable the device 14 toperform RF ranging with the lighting fixtures 14A in order to obtain thedistance measurements discussed above. The lighting networkcommunications adapter 84 may include communications circuitry 88,processing circuitry 90, and a memory 92. The communications circuitry88 is configured to directly communicate with one or more lightingfixtures 14A in the distributed lighting network 10, for example, viathe IEEE wireless communications standard 802.15.4. The memory 92 mayinclude instructions configured to facilitate communication and allowthe device 14 to authenticate itself in the distributed lighting network10.

FIG. 33 illustrates a user interface that may be provided to facilitatethe registration of the subset of the lighting fixtures 14A discussedabove. As shown, a floor plan or other diagram indicative of a realspace may be provided along with a graphical representation of each oneof the lighting fixtures 14A. The user interface may facilitate adrag-and-drop operation in order to place one or more of the lightingfixtures 14A in their correct location in the space, thereby registeringthe coordinates of the lighting fixture 14A. Instructions may beprovided to the user, and an indication of the number of lightingfixtures 14A that must be registered to interpolate the locations of theremaining lighting fixtures 14A may be shown. Notably, FIG. 33 is onlyexemplary. There may be countless ways to facilitate the registration ofthe subset of lighting fixtures 14A, either via a graphical userinterface or otherwise, all of which are contemplated herein.

FIG. 34 is a flow diagram illustrating a process for mapping andregistering lighting fixtures 14A in a distributed lighting network 10according to an additional embodiment of the present disclosure. First,distance measurements between each one of a number of lighting fixtures14A are obtained (step 1700). The distance between each one of thelighting fixtures 14A may be determined via any suitable means, such asRF and acoustic ranging. When using RF ranging an RF signal is sent fromone lighting fixture 14A to another lighting fixture 14A and returned. Aphase of the returned RF signal may be used to determine a distancebetween the lighting fixtures 14A. As another example, a sound may beemitted by one lighting fixture 14A and measured by another. The soundmeasurements may then be used to determine a distance between thelighting fixtures 14A.

Next, the distance measurements obtained above are processed in order toassign coordinates to each one of the lighting fixtures 14A (step 1702),wherein the coordinates indicate the relative locations of the lightingfixtures 14A with respect to one another. In one embodiment, thedistance measurements are processed using multidimensional scaling toobtain the coordinates for each one of the lighting fixtures 14A,however, any suitable processing techniques for transforming distancesbetween objects into a relative coordinate system may be used withoutdeparting from the principles of the present disclosure.

Finally, registration of the coordinates for a subset of the lightingfixtures 14A is facilitated (step 1704). Registering the coordinates fora subset of the lighting fixtures 14A includes associating thecoordinates assigned to each one of the subset of the lighting fixtures14A with coordinates in a desired coordinate space. Registering thecoordinates of a subset of the lighting fixtures 14A allows the relativecoordinates of the lighting fixtures 14A determined above to betranslated into a real coordinate system such that the actual locationof the lighting fixtures 14A is known. Depending on the coordinatesdetermined above, the size of the distributed lighting network 10, andother variables such as the quality of the distance measurements, only asmall number of lighting fixtures 14A may be required in the subset. Forexample, registering the coordinates of two or three of the lightingfixtures 14A may be sufficient to register the remaining lightingfixtures 14A, for example, via interpolating the coordinates of theremaining lighting fixtures 14A with a Procrustes superimposition asdiscussed above. Registering the coordinates of the subset of thelighting fixtures 14A may be accomplished by manually allowing a user toassociate the coordinates with a desired coordinate system. For example,a user interface may be provided, which facilitates a user in providingan absolute location of one or more of the lighting fixtures 14A, forexample, on a floorplan of a building, as discussed above.

FIG. 35 illustrates the process described above. As shown in FIG. 35, anumber of lighting fixtures 14A communicate to obtain a number ofdistance measurements to one another. The distance measurements may beobtained via RF ranging, acoustic ranging, or any other suitabletechniques. Further, multiple techniques may be combined or “fused” toobtain a more accurate distance measurement between two lightingfixtures 14A. While not shown, in some embodiments distance measurementsmay be obtained both between lighting fixtures 14A and between thedevice 14 and the lighting fixtures 14A. These distance measurements maythen be processed together in order to further increase the accuracy ofthe resulting coordinates for each lighting fixture 14A.

The processes discussed above with respect to FIG. 30 and FIG. 34 assumea completely or relatively complete set of distance measurements betweenthe device 14 and each lighting fixture 14A or between each lightingfixture 14A, respectively, to obtain an accurate result. However, thismay not always be the case. In some cases, incomplete distancemeasurements may be obtained. Accordingly, FIG. 36 is a flow diagramillustrating a process for dealing with incomplete distancemeasurements. First, the distance measurements are received (step 1800).A determination is then made whether the distance measurements are acomplete set (step 1802). Such a process may include verifying thatthere exist distance measurements between each lighting fixture 14A andthe device 14, or between each one of the lighting fixtures 14A. In somecases, this step may also include analyzing the data for “bad” distancemeasurements, which may be abnormally long or short, or otherwisesuspect. These distance measurements may be discarded. If the set ofdistance measurements are complete, the distance measurements areprocessed (step 1804) as discussed above. If the distance measurementsare not complete, the distance measurements are pre-processed (step1806). Pre-processing the incomplete distance measurements may includefilling in distance measurements with assumed data or otherwiseattempting to calculate the missing distance measurements. Suchpre-processing may result in groups of lighting fixtures 14A withcoordinates relative to one another. These groups may be overlapping,and thus may need to be merged (step 1808). Pre-processing theincomplete set of distance measurements and merging groups may allow forrelatively accurate coordinates to be assigned to each lighting fixture14A even with incomplete data.

FIG. 37 is a flow diagram illustrating details of facilitatingregistration of the coordinates of one or more of the lighting fixturesas discussed in FIG. 30 and FIG. 34 according to one embodiment of thepresent disclosure. First, the coordinates for the lighting fixtures 14Ain the subset are received along with anchor coordinates (step 1900).The anchor coordinates are the coordinates in the desired coordinatesystem that correspond with the location of a lighting fixture 14A, suchas those indicated by a user in FIG. 33 above. The coordinates for eachlighting fixture 14A are processed using the anchor coordinates (step1902) in order to associate each lighting fixture 14A with a particularlocation in the desired coordinate system. In one embodiment, thecoordinates for each lighting fixture 14A may be processed using aProcrustes superimposition to obtain the location of the lightingfixture 14A as discussed above. These processed coordinates are thenrefined (step 1904), for example, by generating a force-directed layoutof the lighting fixtures 14A.

In some situations, power consumption may be an important concern forthe devices 14 in the distributed lighting network 10. For example,power consumption may be very important in emergency situations in whichone or more of the devices 14 is powered by a battery backup, or inoff-grid applications in which an off-grid energy source is used tocharge a battery, which in turn powers one or more of the devices 14. Asdiscussed above, current solid-state lighting fixtures 14A provide apulse-width modulated current to one or more LEDs in order to provide adesired light output. This pulse-width modulated current is fixed inmagnitude with a modulated duty cycle. The duty cycle thus determinesthe light output of the lighting fixture 14A. In some situations, theefficiency of driving one or more LEDs may be improved.

FIG. 38 is a flow diagram illustrating a method for controlling thebrightness of one or more LEDs according to one embodiment of thepresent disclosure. First, a determination is made regarding whether thebrightness of the LEDs is being adjusted up or down (step 2000). If thebrightness is being adjusted up, a determination is then made regardingwhether a pulse magnitude of a pulse-width modulated signal provided tothe LEDs is less than a predetermined maximum pulse magnitude (step2002). If the pulse magnitude of the pulse-width modulated signal isless than the maximum pulse magnitude, the magnitude of the pulse-widthmodulated signal is increased (step 2004). If the pulse magnitude of thepulse-width modulated signal is not less than the maximum pulsemagnitude, the duty cycle of the pulse-width modulated signal isincreased (step 2006). If the brightness of the LEDs is being adjusteddown, a determination is then made regarding whether a pulse magnitudeof the pulse-width modulated signal is greater than a predeterminedminimum magnitude (step 3008). If the pulse magnitude of the pulse-widthmodulated signal is greater than the minimum magnitude, the pulsemagnitude of the pulse-width modulated signal is decreased (step 2010).If the pulse magnitude of the pulse-width modulated signal is notgreater than the minimum magnitude, the duty cycle of the pulse-widthmodulated signal is decreased (step 2012).

FIG. 39 shows an exemplary pulse-width modulated signal according to oneembodiment of the present disclosure. In particular, FIG. 39 shows apulse width P_(w), a pulse magnitude P_(m), a minimum pulse magnitudeP_(mmin) and a maximum pulse magnitude P_(mmax). When adjusted accordingto the process discussed above, efficiency improvements may be achievedover conventional fixed magnitude pulse-width modulation schemes forsolid-state lighting devices. The minimum pulse magnitude P_(mmin) maybe chosen such that the light output of the lighting fixture 14Amaintains one or more desired parameters such as brightness, color,color temperature, color rendering index, or the like. However, in someembodiments one or more of these parameters may be sacrificed in favorof efficiency. At a certain pulse magnitude P_(m), one or more of thedesired parameters for light output mentioned above will begin tosuffer. While this is generally not desirable, it may be a usefultradeoff in some cases where any quality of light is better than none.Additional actions such as driving only the most efficient LEDs in thelighting fixture 14A or intentionally sacrificing light outputparameters such as color rendering index may be simultaneously usedalong with the power control process discussed above to obtain evenfurther improvements in efficiency at the expense of light outputquality.

In situations such as the aforementioned emergency and off-gridapplications, it may be advantageous to know with precision the powerconsumption of a device 14 in the distributed lighting network 10.Accordingly, FIG. 40 is a flow diagram illustrating a method forcalibrating a power consumption measurement of a device 14 according toone embodiment of the present disclosure. Such a calibration process mayoccur, for example, after assembly. First, if the device 14 is alighting fixture 14A, the LED array 24 is turned off (step 2100). If thedevice 14 is not a lighting fixture 14A, there is no LED array 24 toturn off, and thus this step may be skipped. The standby powerconsumption of the device 14 is then measured (step 2102) and stored(step 2104). Once again, if the device 14 is a lighting fixture 14A, theLED array is turned on (step (2006). An active power consumption of thedevice 14 is then measured (step 2108) and stored (step 2110). Indevices 14 other than lighting fixtures 14A, these steps may not beperformed, as they may not be necessary. The stored power consumptionvalues may be used to more accurately determine the instantaneous orhistorical power consumption of the device 14. Such measurements mayincrease the accuracy of power consumption of the devices 14 such thatpower metering can be performed by one or more of the devices 14 in thedistributed lighting network 10.

One use for the aforementioned power consumption data is in PoE devices14 in the distributed lighting network 10. PoE devices 14 are capable ofrequesting a given amount of power from a switch 14E. Generally, PoEdevices 14 are configured to request an amount of power that is equal tothe maximum possible power draw of the device 14. However, the device 14may rarely consume this much power. Accordingly, FIG. 41 is a flowdiagram illustrating a method of requesting power from a switch 14E inorder to improve the efficiency thereof. First, the power consumption ofa device 14 is determined (step 2200). An updated request for power isthen sent from the device 14 to a switch 14E (step 2202). The updatedrequest is based on the determined actual power consumption of thedevice 14, which may be instantaneously updated, averaged and updatedperiodically, or updated in any other way. A determination is then maderegarding whether the power consumption of the device 14 has changed(step 2204). If the power consumption of the device 14 has changed, theprocess starts again at step 2200. If the power consumption of thedevice 14 has not changed, the process starts again at step 3204.Requesting only the power that is instantaneously required by a device14 may significantly improve the efficiency of the wired lightingnetwork 12B, as each switch 14E no longer has to deliver power to eachdevice 14 based on the maximum possible power requirements of thatdevice.

The foregoing power saving techniques may be especially useful inoff-grid lighting fixtures 14A, the details of which are illustrated inFIGS. 42A and 42B. As shown in the Figures, an off-grid lighting fixture14A includes a body 94, a light source 96, a battery 98, and aphotovoltaic panel 100. The body 94 houses the light source 96, andfurther includes the driver circuitry 22 and other necessary componentsof the lighting fixture 14A. The battery 98 is located on top of thebody 94, and in particular may be fused with the body 94. Further, thephotovoltaic panel 100 is located on top of the battery 98. Notably, thephotovoltaic panel 100, the battery 98, and the light source 96 arelocated directly adjacent to one another. This is so that energygenerated by the photovoltaic panel 100 and provided by the battery 98are maximized, and efficiency is not degraded in the transport of saidenergy to the light source 96. Notably, FIGS. 42A and 42B are merelyexemplary embodiments of an off-grid lighting fixture 14A. Numerousdifferent configurations may exist for the body 94, the battery 98, andthe photovoltaic panel 100, all of which are contemplated herein.

FIG. 43 is a block diagram illustrating details of the operationalcircuitry of the off-grid lighting fixture 14A according to oneembodiment of the present disclosure. The off-grid lighting fixture 14Ashown in FIG. 43 is substantially similar to the lighting fixture 14Adiscussed above with respect to FIG. 2, except that the input voltagesource is replaced with an off-grid power source 102 and a battery 104.The off-grid power source may be any suitable off-grid power source, andmay be a renewable energy source such as a photovoltaic panel or a windturbine. The off-grid power source 102 charges the battery 104, which inturn provides the necessary power for the driver circuitry 22.

FIG. 44 is a block diagram illustrating details of the operationalcircuitry of the off-grid lighting fixture 14A according to anadditional embodiment of the present disclosure. The off-grid lightingfixture 14A shown in FIG. 44 is substantially similar to that discussedabove with respect to FIG. 4, except that the input voltage source isreplaced with an off-grid power source 102 and a battery 104. Theoff-grid power source 102 may be any suitable off-grid power source, andmay be a renewable energy source such as a photovoltaic panel or a windturbine. The off-grid power source 102 charges the battery 104, which inturn provides the necessary power for the driver circuitry 22.

The intelligence of the off-grid lighting fixture 14A may be especiallyuseful in off-grid applications. In addition to merely providing light,the off-grid lighting fixture 14A may measure environmental parameters,provide security, and the like. Further, a number of off-grid lightingfixtures 14A may form the distributed lighting network 10, which may beused for communication, and further may distribute wireless or wiredcommunications signals received from other sources. For example, anoff-grid lighting fixture 14A may act as a base-station for cellularsignals in some embodiments. In general, the intelligence of theoff-grid lighting fixture 14A may significantly enhance its utility asan off-grid device.

In some situations, due to communications network restraints and otherfactors it may be desirable to communicate information with one or moredevices 14 in the distributed lighting network 10 via optical means. Forexample, lighting fixtures 14A that are mounted very high in a warehousein which wired or wireless communications are not possible may need tobe configured. One example of such a fixture is described in co-filedU.S. Patent Publication No. 2017/0227207 filed Feb. 8, 2016 and titled“Led Luminaire Having Enhanced Thermal Management”, the disclosure ofwhich is hereby incorporated by reference in its entirety.Conventionally, an individual would have to climb a ladder or otherwiseaccess each lighting fixture 14A in the distributed lighting network 10in this situation in order to perform such configuration. If each device14 is equipped with an image sensor, however, such configuration may besignificantly simplified. FIG. 45 shows an example of suchconfiguration. As shown in FIG. 45, an optically encoded medium (e.g., abarcode, a QR code, or even a particular color or array of colors) maybe presented within a field of view of an image sensor within a lightingfixture 14A. The image sensor in the lighting fixture 14A may read theinformation from the optically encoded medium and adjust one or moresettings based thereon.

FIG. 46 is a flow diagram illustrating a method for changing one or moresettings of a device 14 based on one or more optical indicators. First,the environment is scanned for optical indicators (step 2300). Asdiscussed above, this is likely performed by an image sensor, however,any suitable means for finding optical indicators in the surroundingenvironment may be used without departing from the principles of thepresent disclosure. A determination is then made whether an opticalindicator has been found (step 2302). If an optical indicator has beenfound, one or more settings of the device 14 are adjusted based on theoptical indicator (step 2304). If an optical indicator has not beenfound, the process returns to step 2300 where the environment is scannedfor optical indicators. Using the process described above, settings fordevices 14 that are otherwise inaccessible via wired or wirelesscommunications means and difficult to physically access may be changedeasily.

As discussed above, providing a number of different sensors on devices14 that are distributed throughout a space has enumerable benefits. Ingeneral, the sensor data obtained from these devices is highly valuablebecause of the nature of a distributed lighting network 10. Lightingfixtures 14A enjoy a relatively widespread pre-existing infrastructureof power. Further, lighting fixtures 14A are generally distributedrelatively evenly and consistently throughout a space. By providinglighting fixtures 14A and other devices 14 that capitalize on theseattributes, a large network of sensors that are distributed throughout aspace can be achieved. Such a network of sensors may provide an immenseamount of information about a space, and may be used to providesignificant advances in the functionality of a space.

A general framework for utilizing the sensor data obtained in thedistributed lighting network 10 is shown in FIG. 47. First, sensor datafrom one or more devices 14 in the network is obtained (step 2400). Thesensor data is then analyzed (step 2402). This analysis may comprise anynumber of different signal processing and/or analysis techniques, someexamples of which are provided below. One or more environmentalconditions are then determined from the analyzed sensor data (step2404). Some examples of these environmental conditions are discussed indetail below. A determination is then made whether the sensor data haschanged (step 2406). If the sensor data has changed, the sensor data isanalyzed again at step 3402 and one or more environmental conditions aredetermined again at step 2404. This process may repeat periodically orpersistently, and the determined environmental conditions may be used inany number of ways to improve the management of a space or gain insightsabout the use thereof. If the sensor data has not changed, the processwaits for the sensor data to change.

For example, FIG. 48 shows a similar process to that shown in FIG. 47wherein the sensor data is used to adjust one or more parameters of abuilding management system. First, sensor data from one or more devices14 in the network is obtained (step 2500). The sensor data is thenanalyzed (step 2502), and the analyzed sensor data is used to adjust oneor more parameters of a building management system (step 2504). Forexample, the sensor data may be used to adjust a temperature of athermostat, the amount of fresh circulating air into a space, or thelike. A determination is then made regarding whether the sensor data haschanged (step 2506). If the sensor data has changed, the sensor data isanalyzed again at step 2502 and the one or more building managementsystem parameters are adjusted at step 2504. If the sensor data has notchanged, the process waits for the sensor data to change.

Examples of environmental conditions and their uses are discussed below.With regards to an ALS, such a sensor may be used as discussed above todetect ambient light levels in a space. One or more lighting fixtures14A may then change the light output thereof in order to maintain aconsistent amount of light on a task surface below the lightingfixture(s) 14A. Further, an ALS may be used to detect a modulating lightsignal in order to participate in the automatic grouping processdiscussed above and/or to decode data in a modulated light signal.Additionally, ALS measurements obtained from multiple devices 14 in thedistributed lighting network 10 may be used to determine a “sun load” ofa space. That is, ALS measurements obtained from multiple devices 14 inthe distributed lighting network 10 may detect the amount of sunlight ina given space. This information may be used to predictively adjust oneor more heating or cooling parameters in order to more accurately heatand/or cool a space. Further, such information may be used to adjustautomated blinds and/or smart windows in order to adjust the amount ofsunlight entering a space. Since current methods of heating and/orcooling by taking temperature measurements at a number of differentthermostats located throughout a space may result in a wide temperatureswing within a given space, such information may allow the temperatureof a space to be more accurately maintained and thus maintain a morecomfortable environment.

Regarding an accelerometer or other motion sensor, this sensor data maybe used to detect occupancy as discussed above. Further, anaccelerometer or other motion sensor may be used to detect whether adevice 14 is properly oriented (e.g., whether a pole-mounted device 14is leaning or otherwise improperly mounted). The same orientationinformation may be used to determine if a device 14 is moving (e.g.,swaying), and thus may be used, in the case of devices 14 that areoutdoors, to detect wind speed, earthquakes, and structural stability.The sway of a device 14 that is located outside may be directlycorrelated with the wind speed, and thus such information may beobtained from an accelerometer or other motion sensor. Measuring seismicactivity via a distributed network of devices 14 may prove immenselyvaluable, since the devices 14 are relatively close together and thusmay provide valuable insights about the fine-grained distribution ofseismic activity. Such information may be used to predict earthquakes orother seismic activity in the future. When placed on a structure such asa bridge, devices 14 may provide valuable insight regarding thestructural integrity of the structure, for example, by examiningresonant vibration patterns of the structure. Such information may beused to provide alerts if a structure becomes dangerously unstable ormay be used to dictate required maintenance of a structure over time.

Regarding an image sensor, such a sensor may be used to detect occupancyevents and ambient light levels as discussed above. Further, theflexibility of an image sensor may be used to analyze traffic (e.g.,human traffic in an indoor space, automobile traffic in an outdoorspace, and high-traffic lanes on a factory floor), may be used todetermine empty parking spots in a parking garage, may be used todetermine waiting times (e.g., length of register lines), and may beused to differentiate between customers and associates in a retailestablishment in order to match associates with customers that needassistance. As image processing techniques continue to improve, theinformation about a space that may be obtained is virtually endless.Examples of using an image sensor to analyze a space are included inU.S. patent application Ser. No. 14/827,007, the disclosure of which ishereby incorporated by reference in its entirety.

Other types of image sensors may provide additional data that may beused in the distributed lighting network 10. For example, low-resolutionIR imaging (e.g., forward looking infrared imaging sensors) may be usedto increase the efficacy of occupancy detection, may be used to detectfires, may be used to detect hot-spots in a space for HVAC controlpurposes, may be used to predict maintenance on machines in a factory(e.g., by detecting changes in the normal temperature signaturesthereof), and the like. Further, time of flight (TOF) imaging sensorsmay be used to construct three-dimensional representations of a space,which may be used for building reconstruction and/or modeling.

Regarding temperature and humidity sensors, such sensors may be used toprovide more fine-grained information to an HVAC system controlled by aBMS, which may use the information to better control the environmentalconditions in a space. In outdoor applications, temperature and humiditysensors may provide fine-grained temperature measurements that may notonly give an accurate representation of the weather, but may also beused to predict future weather conditions. Additional sensors such aswind speed sensors and the like may be used to further increase theinformation available to outdoor devices 14. Since outdoor devices 14may be distributed in large numbers throughout a space, weather patternsthat were previously undetectable may become apparent and increase theaccuracy of weather forecasting.

Regarding barometers or other atmospheric pressure sensors, such sensorsmay be used to differentiate between floors of a building as discussedabove in order to facilitate network formation, may be used to detectoccupancy either alone or in combination with one or more other sensors,and may be used to determine or predict the weather as discussed above.

Regarding air quality sensors such as carbon dioxide sensors, carbonmonoxide sensors, VOC sensors, and smoke sensors, such sensors may beused to provide an accurate representation of the air quality in aspace. This information may be used to circulate fresh air into a spacevia a building management system, or may be used to identify dangerousconditions that require evacuation or other corrective measures. Alarmsand alerts may be provided as necessary based on the sensormeasurements.

Regarding spatial sensors such as GPS sensors and magnetometers,measurements from these sensors may be used for georegistration ofdevices 14 and/or the images therefrom, may provide a synchronized clock(GPS), and may provide an orientation of a device. In general, spatialsensors may be used to identify the precise location of a device 14.This location information may be shared with other devices 14, includingremote devices 16. Since devices 14 in the distributed lighting network10 will generally remain stationary, a very accurate location may beobtained based on measurements from spatial sensors. This locationinformation may be much more accurate, for example, than locationinformation obtained from a mobile remote device 16, and thus may beshared with said remote device 16. In other cases, one or more remotedevices 16 may not have access to location information and thus mayobtain it from one or more devices 14 in the distributed lightingnetwork 10.

Regarding ultrasonic sensors, such sensors may be used to “image” anenvironment in a three-dimensional manner, and further may assist inobject detection and occupancy event detection.

Regarding microphones and/or speakers, measurements from these devicesmay be used to detect occupancy events as described above. Further,measurements from these devices may be used to detect auditory events(e.g., clapping), which may be used to control one or more devices 14 inthe distributed lighting network 10, and may be used to identify events(e.g., shots fired, screaming, shouting, or the like). Eventclassification based on detected sound may be performed by each device14 in a lightweight manner or analyzed in detail by a remote device 16.Providing a microphone and speaker in each device 14 in the distributedlighting network 10 also allows for the detection and analysis of voicecommands, which may simplify the control and operation of thedistributed lighting network 10, and may allow for the delivery of audiomedia (e.g., music, radio, podcasts, or the like) to devices 14throughout the distributed lighting network 10 as desired.

In some embodiments, the communications circuitry of a device 14 mayinclude Bluetooth communications circuitry. Such communicationscircuitry may allow the device 14 to pair with one or more mobiledevices, for example, to make calls, play music, or simply detect when amobile device is nearby. Further, the communications circuitry mayinclude radio frequency identification (RFID) receiver and/ortransmitter circuitry. Accordingly, one or more devices 14 may detect,for example, an RFID tag in a badge or key fob and grant or deny accessto a particular space based thereon.

The analysis discussed above with respect to the various sensormeasurements may be performed locally by each device 14 in thedistributed lighting network 10, may be performed in a distributedmanner throughout the distributed lighting network 10, may be performedby a single device 14 such as a border router 14D, or may be performedby a remote device 16. Using a remote device 16 to analyze sensor datafrom the various devices 14 in the distributed lighting network 10 mayallow for extensive analysis using techniques such as deep machinelearning, artificial intelligence, and the like. As discussed above, oneor more border routers 14D may facilitate the retrieval of sensor datafrom each device 14, for example, via an API with which a remote device16 interfaces.

One notable feature that may be facilitated by the inclusion ofmicrophones and speakers in the devices 14 of the distributed lightingnetwork 10 is discussed with respect to FIGS. 49 and 42. Specifically,FIG. 49 illustrates an intra-network communication process, while FIG.50 illustrates an inter-network communication process. First, networkcommunication is initiated (step 2600). Such communication may beinitiated, for example, by a voice command (e.g., “Call John”), or byany other suitable means. A network end point is then determined for thecommunication (step 2602). This may be accomplished, for example, by alook-up table regarding the location of the individual with whomcommunication was requested, may involve the use of one or more sensorsto locate an individual, or may be accomplished by any other suitablemeans. A communication channel is then opened with the end point (step2604). For example, bidirectional voice communication may be initiatedwith the network end point and the initiating device 14.

FIG. 50 illustrates a similar process for inter-network communication.First, network communication is initiated (step 2700). A network endpoint is then determined for the communication (step 2702). Acommunication channel is then opened with the end point, which is aremote device 16 (step 2704). Notably, this communication is routedthrough an external network, which is facilitated by a border router14D. In one embodiment, the remote device 16 is a wirelesscommunications device, and thus communication is initiated through acellular network. Using the processes outlined above, communication maybe initiated with individuals in or outside the distributed lightingnetwork 10 in a convenient manner.

As discussed above, devices 14 in the distributed lighting network 10may use sensor data to calibrate or otherwise change their behavior overtime. For example, devices 14 in the distributed lighting network 10 mayautomatically group with one another, or may adjust calibrationthresholds based on historical data in order to increase the accuracy ofevent detection and response. Accordingly, it may be desirable in somecircumstances to leverage the calibration that has been accomplished bya set of devices 14 for a different set of devices 14 in the distributedlighting network 10. For example, devices 14 that have been installedand running for a period of time may include calibration informationthat is useful for newly installed devices 14. Accordingly, FIG. 51 is aflow diagram illustrating a method of copying device settings from onedevice 14 or group of devices 14 to another device 14 or group ofdevices 14 in the distributed lighting network 10. First, devicesettings are obtained from a desired set of devices 14 (step 2800) andstored (step 2802). The device settings are then transferred to a set ofdifferent desired devices 14 (step 2804). These settings are thenimplemented on the different desired devices 14 (step 2806). Copyingsettings in this manner may allow newly installed devices 14 the benefitof the automatic calibration performed by devices 14 that have been upand running for a period of time, and thus may reduce the period of timenewly installed devices 14 need for calibration.

In general, providing numerous sensors into the devices 14 of thedistributed lighting network 10 enables significant improvements infunctionality thereof. Using the sensor data may allow for extremelyaccurate occupancy detection as discussed above. However, it may alsoallow for vacancy detection. Detecting vacancy in certain areas of aspace may allow for power saving techniques to be implemented by thedistributed lighting network 10, for example, by lowering or turning offthe lights in that area, lowering or turning off HVAC in that area, orthe like. The sensor data may further allow for counting the number ofpeople in a space or a sub-space. This may be a useful analytic toolthat can allow building designers to optimize spaces for energyefficiency, improved worker productivity, and the like. Similarly, thesensor data may allow for tracking movement patterns and/or flowdirection of the people within a space or sub-space. Once again, thismay allow building designers to shape the foot traffic within a space,which may lead to improved energy efficiency, better workerproductivity, and the like.

In a more general sense, the sensor data may allow for the tracking ofobjects within a space or sub-space. For example, inventory may betracked overhead via the distributed lighting network 10. As discussedabove, people may also be tracked. In some embodiments, the sensor datamay be of sufficiently high resolution to identify specific inventory(e.g., via optical coded information such as barcodes or QR codes,object recognition, or any other means) within a space or particularpeople (e.g., via facial recognition, gait recognition, or any othermeans) within a space. Such fine-grained detection may enable certainapplications such as personalization of building settings (light, HVAC,etc.) based on the detection of certain inventory and/or people within aspace or sub-space. This may be especially useful in healthcaresettings, where patient room comfort settings (e.g., light colortemperature, temperature, sound, window shades) may be adjusted toincrease patient comfort and thus improve patient outcomes. In caseswhere thermal data is important, the sensor data may allow for thetracking of the thermal state of one or more objects and/or people. Thismay be useful for tracking the thermal performance of temperaturecritical objects such as servers in a server room or for monitoring thetemperature of people, which may be useful in healthcare settings and/oras a first step for screening ill people.

As discussed above, the sensor data may be used to detect entry pointsand exits to a space or sub-space, as well as to automatically map thedevices 14 in the distributed lighting network 10 and thus the space inwhich it is located. The sensor data may also be useful for providing“daylight harvesting,” in which light provided from devices 14 in thedistributed lighting network 10 is adjusted based on the amount of lightprovided via windows in a space. To do so, the sensor data maycharacterize the amount of sunlight and/or UV light within a space orsub-space. Further, the sensor data may enable light quality monitoringwithin a space (e.g., amplitude, color, color temperature, colorrendering index), which may have an effect on the people working withinthat space. This data may allow for the adjustment of light provided bythe devices 14 in the distributed lighting network 10, for example, tooptimize productivity, relaxation, or the like, at certain times of day.This may be particularly useful, for example, in educational settingswhere learning may be improved by adjusting the light to increase focusand awareness and classroom behavior may be improved by adjusting thelight to increase relaxation. Further, this may be particularly usefulin healthcare settings, where light can be used to promote rest andsleep, thus improving patient outcomes.

The sensor data may allow for the monitoring of input power to thedevices 14 in the distributed lighting network 10 and thus may be usedto provide power consumption metering. The sensor data may also be usedto provide air quality monitoring (e.g., VOC, particle count, smokedetection, etc.) within a space or sub-space. Similarly, the sensor datamay enable environmental monitoring (e.g., humidity, temperature,pressure, etc.) within a space or sub-space. Such environmentalmonitoring may be tailored to desired applications, such as detectingearthquakes, loud noises (e.g., crashes, gun shots), or ambient noiselevels. The detailed environmental information provided by the sensordata may enable for smarter operation of building systems such as HVAC.Instead of cycling HVAC on a time-based schedule, the sensor data mayenable the operation thereof on an as-needed basis to optimizeenvironmental conditions such as air quality, which may save money andfurther increase the healthiness of the indoor environment in certainconditions. In general, operating the HVAC and other building systemsbased on the sensor data may allow for optimizing cost, environmentalquality, and the like.

The sensor data may enable applications such as audio/video recording,security systems with audible alarms, and gesture control of the devices14 or other devices in communication with the distributed lightingnetwork 10. If the sensor data is of sufficient resolution, it mayreplace certain building management system functions such as dooraccess.

The light providing capabilities of some of the devices 14 may enableapplications such as emergency egress indication in which paths toemergency exits are illuminated on the detection of adverse conditions.This path indication may similarly be useful for directing emergencyresponders to a person or condition in a space or sub-space. Further,this path indication may be used for indoor navigation applications asdiscussed below. In general, the devices 14 may provide increasedsituational awareness and thus improved outcomes in both emergency andnon-emergency situations.

Indicators on the devices 14 in the distributed lighting network 10 suchas speakers, light indicators, and the like may be used to communicateinformation throughout a space or sub-space. For example,accessibility/disability guidance, severe weather and/or emergencynotifications, or simply announcements may be provided from the devices14 in the distributed lighting network 10, essentially replacing thefunction of an announcement system.

The sensor data may not only provide information about the surroundingenvironment but also the internal operation thereof. This may enablepre-emptive maintenance of the devices 14 in the distributed lightingnetwork 10 with minimal downtime. For example, the devices 14 maymonitor internal power consumption, battery life, light output, and thelike to ensure that they are functioning properly, reporting thesemetrics and thus enabling the monitoring of device health.

Additional functional modules may be incorporated into one or more ofthe devices 14 in the distributed lighting network 10 to enableadditional applications thereof. For example, white noise generators,networking equipment (Wi-Fi, Li-Fi, etc.), and the like may beincorporated into one or more of the devices 14 to provide additionalfunctionality. Since the devices 14 are generally already coupled to apower source, they provide a pre-existing and thus convenient platformfor these additional functional modules.

In general, the sensor data may provide many useful insights about thespace in which the distributed lighting network 10 is located. Theseinsights may prove exceptionally useful when paired with buildingmanagement systems. As discussed above, much of the insights derivablefrom the sensor data allow HVAC systems to be used more efficiently toprovide better environmental conditions. Further, the sensor data mayenhance or replace security systems. By using the sensor data from thedistributed lighting network 10, building management systems may improvebuilding operation in myriad ways, increasing occupant and managementsatisfaction, and often decreasing energy consumption and thus buildingmanagement costs.

FIGS. 52A and 52B illustrate an exemplary lighting fixture 14A that maybe used in an indoor setting according to one embodiment of the presentdisclosure. The lighting fixture 14A includes a lens 106 and a square orrectangular outer frame 108. The lens 106 is coupled to and extendsbetween opposite sides of the outer frame 108, and may be substantiallyarc-shaped, such that an outer surface of the lighting fixture 14Aappears as a half-circle. Further, the lens 106 may include a sensormodule cover 106A, which is a portion of the lens 106 that is removablein order to provide access to a sensor module connector and space for asensor module 14B to be connected to the lighting fixture 14A. The outerframe may optionally be surrounded by a shroud 108A, which gives thelight a troffer-style appearance and may provide additional mountingoptions for the lighting fixture 14A, as shown in FIG. 52B. Further, theouter frame 108 may include a number of flat mounting surfaces 108B,which extend outwards and include one or more mounting holes formounting the lighting fixture 14A, for example, to a ceiling.

With respect to the process for mapping and registering lightingfixtures 14A discussed above with respect to FIG. 34 and FIG. 35, such aprocess may require increased accuracy in certain applications. Forexample, in applications in which the lighting fixtures 14A are used toprovide indoor location services to mobile devices in the indoor spacein which the lighting fixtures 14A are located, the location of each oneof the lighting fixtures 14A in the indoor space must be very accurate.Accordingly, FIG. 53 is a flow diagram illustrating a process formapping and registering lighting fixtures 14A with increased accuracyaccording to one embodiment of the present disclosure. To begin, a firstset of distance measurements between each one of the lighting fixtures14A is obtained using a first measurement method (step 2900). The firstmeasurement method may include RF ranging, acoustic ranging, and/or“lightcasting” and “lightcatching” as discussed in detail above.Notably, the first measurement method may include any suitable methodfor determining a distance between two of the lighting fixtures 14A. Insome embodiments, a camera on each one of the lighting fixtures 14A maybe used to detect a modulated light signal from another one of thelighting fixtures 14A such that both a magnitude and a direction of themodulated light signal can be determined. Details of such an approachare described in co-assigned U.S. Pat. No. 9,769,900, the contents ofwhich are hereby incorporated by reference in their entirety.

A second set of distance measurements between each one of the lightingfixtures 14A is obtained using a second measurement method that isdifferent than the first measurement method (step 2902). For example, ifthe first measurement method includes RF ranging, the second measurementmethod may include acoustic ranging, “lightcasting” and “lightcatching,”or any other suitable method for measuring distances between thelighting fixtures 14A. The first set of distance measurements and thesecond set of distance measurements are then processed to assignrelative coordinates to each one of the lighting fixtures 14A (step2904). Processing the first set of distance measurements and the secondset of distance measurements to assign relative coordinates to thelighting fixtures 14A may be accomplished using several well-knownspatial processing techniques, such as force-directed graphing,Procrustes superimposition, and the like, as discussed above. Further,the first set of distance measurements and the second set of distancemeasurements may be processed by a machine learning algorithm trainedusing known locations of a number of lighting fixtures and data from thefirst measurement method and the second measurement method. Such amachine learning algorithm may be pre-trained and loaded on one or moredevices 14 in the distributed lighting network 10, or may be dynamicallytrained based on information provided by one or more administrators ofthe distributed lighting network 10.

The relative coordinates for each one of the lighting fixtures 14A arethen registered to a real coordinate system (step 2906). As discussedabove, the distance measurements obtained between the lighting fixtures14A are completely relative to one another. That is, in many cases thedistance measurements are not absolute and thus do not correspond to anyparticular unit of measurement, hence the use of the term “relative”coordinates. In order to obtain a usable representation of the lightingfixtures 14A with respect to one another, it is thus necessary toregister the relative coordinates to a real-world coordinate system inwhich the coordinates correspond to known units of distance measurement(e.g., feet, meters, etc.). In some embodiments, the registration may beaccomplished using registered coordinates for a subset of the lightingfixtures (step 2908), however, this information may not always beavailable and thus is shown as a dashed box. It is then determinedwhether a refresh timeout has occurred (step 2910), indicating that themapping and registration process discussed above should be performedagain. If a refresh timeout has occurred, the process starts over atstep 2900. If a refresh timeout has not occurred, the process continuesto wait at step 2910. The refresh timeout may be set to constantlyupdate the locations of the lighting fixtures 14A such that the lightingfixtures 14A are able to adapt to changing environmental conditions inthe indoor space in which they are located, such as movable walls,re-arrangement of office furniture, open and closed doors, newly addedlighting fixtures 14A and the like. Accordingly, the lighting fixtures14A are able to maintain an accurate location for themselves and/orrefine their initially determined location without manualreconfiguration, even when the indoor space in which they are locatedchanges.

The process discussed above may be performed by an indoor locationservices module, the functionality of which may be distributed among oneor more devices 14 in the distributed lighting network 10,self-contained on one or more devices 14 in the distributed lightingnetwork 10, or located on a remote device not in the distributedlighting network 10, which may be accessed via one or more devices 14 inthe distributed lighting network 10 (e.g., a border router 14D).

FIG. 54A shows details of registering the relative coordinates for eachone of the lighting fixtures 14A (step 2906 in FIG. 53) according to oneembodiment of the present disclosure. In particular, FIG. 54A showsdetails of registering the relative coordinates for each one of thelighting fixtures 14A when the registered coordinates for the subset ofthe lighting fixtures 14A are available (step 2908 in FIG. 53). In thiscase, relative coordinates for each one of the lighting fixtures 14A areobtained by interpolating registered coordinates for each one of thelighting fixtures 14A not in the subset of the lighting fixtures 14Ausing the relative coordinates for the subset of the lighting fixtures14A (step 2906A). Those skilled in the art will appreciate that given arelationship between relative coordinates and registered coordinates fora number of lighting fixtures 14A, the registered coordinates for theremaining lighting fixtures 14A can easily be interpolated.

As discussed above, the registered coordinates for the subset of thelighting fixtures 14A may be obtained via user input. However, it isdesirable to map and register the lighting fixtures 14A without inputfrom a user. In such a case, the registered coordinates for the subsetof the lighting fixtures (step 2908 in FIG. 53) are not obtained. Asshown in FIG. 54B, the relative coordinates of the lighting fixtures 14Aare scaled to match a scale of a real coordinate system (step 2906A). Inone exemplary embodiment, the bounds of the relative coordinate systemin which the relative coordinates for each one of the lighting fixtures14A exist are compared to the bounds of the real coordinate system todetermine if a scale of the relative coordinate system matches the realcoordinate system. This may be accomplished, for example, by examiningthe resolution of coordinate points between the bounds of the coordinatesystems and attempting to match this resolution between the coordinatesystems. In some embodiments, the above-mentioned first measurementmethod and second measurement method may enable the lighting fixtures14A to not only measure the distances between themselves but also detectwalls and other bounds of the indoor space in which they are located.These bounds may be compared and matched to the bounds of the realcoordinate system in order to properly scale the relative coordinatesystem to match the real coordinate system. Further, an approximate orabsolute distance between each one of the lighting fixtures 14A is oftenknown (specified by building codes, standard practice, blueprints, etc.)without any input from a user. This known distance between the lightingfixtures 14A can be used to match a scale of the relative coordinatesystem determined by comparing the relative distance measurementsbetween the lighting fixtures 14A to this known distance. Groups for thelighting fixtures 14A may also be obtained as described above. That is,it may be known that certain subsets of the lighting fixtures 14A arecollocated in a room, hallway, or the like. Using this information alongwith the known distance between the lighting fixtures 14A may alsoassist in the proper scaling of the relative coordinate space to thereal coordinate system, as there may be separate spaces in the realcoordinate system (e.g., rooms) that can only fit a certain number oflighting fixtures given the known distance between them. Thisinformation may further help to accurately scale the relative coordinatesystem so that the grouped lighting fixtures 14A fit into the separatespaces of the real coordinate system.

Next, the relative coordinates are translated to match a translation ofthe real coordinate system (step 2906B). This may be accomplished inmuch the same way as the scaling discussed above. In particular, boundsof the relative coordinate system may be matched with bounds of the realcoordinate system such that a translation of the relative coordinatesystem matches the real coordinate system. In addition to the above, anarrangement of the lighting fixtures 14A is often known without anyinput from a user. For example, it may be known (e.g., from buildingcode, standard practice, blueprints, etc.) that the lighting fixtures14A are arranged in a grid, an offset grid, or the like. Thisinformation may also be used to properly align the lighting fixtures 14Ain the relative coordinate system and thus assist in the propertranslation of the relative coordinate system to the real coordinatesystem. With the proper arrangement of the lighting fixtures 14A, it maybe easy to match a shape of the relative coordinate system (e.g., longrectangle, L shape, etc.) to a shape of the real coordinate systemresulting in a proper translation between the relative coordinate systemand the real coordinate system. Finally, features of the relativecoordinate system may be matched to features of the real coordinatesystem (step 2906C). As discussed above, this may involve matchingboundaries of the relative coordinate system to the real coordinatesystem, a shape of the relative coordinate system to the real coordinatesystem, and the like. Further, more detailed environmental featuresdetected by sensors on the lighting fixtures (e.g., images obtained froma camera, obstacles detected by acoustic sensors, light sensors, etc.,and the like) may be matched with known features of the real coordinatesystem such that the relative coordinate system is properly scaled andtranslated. The result is a registered coordinate for each one of thelighting fixtures 14A, which describes a location of the lightingfixtures 14A in a real coordinate system that is easily interpretable bya user.

FIG. 55 illustrates the process discussed above with respect to FIG.54B. In particular, FIG. 55 shows the lighting fixtures 14A in arelative coordinate system 110 obtained by processing the first set ofdistance measurements and the second set of distance measurements. Dueto the relative nature of the first set of distance measurements and thesecond set of distance measurements discussed above, the relativecoordinate system 110 is not properly scaled or translated with respectto a real coordinate system 112, represented by a floor plan of theindoor space in which the lighting fixtures 14A are located. Using theprocess described above with respect to FIG. 54B, the relativecoordinate system 110 may be properly scaled and translated with respectto the real coordinate system 112, thus registering the coordinates foreach one of the lighting fixtures 14A and providing a usable locationfor them.

Notably, the processes described above are able to obtain a location foreach one of the lighting fixtures 14A as a set of registered coordinatescorresponding to a real coordinate system. This real coordinate systemmay correspond with a blueprint, floorplan, or a computer implementedrepresentation thereof (e.g., a CAD model), and thus the location ofeach one of the lighting fixtures 14A may be graphically illustratedwhen desired. In some cases, however, the distributed lighting network10 may not have access to such information. It thus may be desirable insome circumstances for the distributed lighting network 10 to generate ablueprint, floorplan, etc. based on information obtained from thelighting fixtures. FIG. 56 illustrates such a process. First, a firstset of distance measurements between each one of the lighting fixtures14A is obtained using a first measurement method (step 3000). Asdiscussed above, the first measurement method may include any suitableway to measure a distance between the lighting fixtures 14A. A secondset of distance measurements between each one of the lighting fixtures14A is also obtained (step 3002). Other environmental measurements mayalso be obtained by the lighting fixtures 14A (step 3004). Theseenvironmental measurements may include images from a camera, informationabout environmental obstacles (e.g., walls, doors, furniture) obtainedfrom the camera, a light sensor, an acoustic sensor, or any othersuitable sensor, and any other environmental measurements. The first setof distance measurements, the second set of distance measurements, andthe environmental measurements may then be processed to generate a mapof the indoor space in which the lighting fixtures 14A are located (step3006). The map may be in the form of a blueprint, a floorplan, or thelike. The map may be easily presented via a graphical user interface,and may show features of the indoor space such as walls, doors,furniture, and the like. In one embodiment, images from cameras on thelighting fixtures 14A may be analyzed to determine areas of overlapbetween the lighting fixtures 14A, thus allowing for a complete top-downview of the indoor space in which the lighting fixtures 14A are located.Such a complete view allows for the formation of a very accurate view ofwalls, doors, and other environmental features seen by the lightingfixtures. The distance measurements may be used along with thisinformation to not only properly arrange the lighting fixtures in arepresentation of the indoor space, but also generate a usable map. Itis then determined if a refresh timeout has occurred (step 3008),indicating that the mapping process should be performed again. If arefresh timeout has occurred, the process starts over at step 3000. If arefresh timeout has not occurred, the process continues to wait at step3008. The refresh timeout may be set to constantly update the map of thelighting fixtures 14A such that the lighting fixtures 14A are able toadapt to and provide an updated map for changing environmentalconditions in the indoor space in which they are located, such asmovable walls, re-arrangement of office furniture, open and closeddoors, and the like.

The above location and map information may be especially useful when thelighting fixtures 14A are used to provide indoor location services. FIG.57 illustrates one such way in which this may be accomplished. As shownin FIG. 57, the lighting fixtures 14A in the distributed lightingnetwork 10 may provide a wireless beacon signal BEAC, which is receivedby a mobile device 16, which in the present case is a mobile device 16in the indoor space in which the lighting fixtures 14A are located. Eachone of the wireless beacon signals BEAC may specify the lighting fixture14A from which it was broadcast (e.g., via a unique identifier) andinclude distance information specifying an approximate distance of themobile device 16 from the lighting fixture 14A. For example, thewireless beacon signal BEAC may be a Bluetooth low energy beacon signal,the details of which will be appreciated by those skilled in the art.The mobile device 16 may communicate with an indoor location servicesmodule in order to determine its location in the indoor space in whichthe lighting fixtures 14 are located.

FIG. 58 is a flow chart illustrating one way in which this may beaccomplished. First, each one of the lighting fixtures 14A provides awireless beacon signal as discussed above (step 3100). The location ofthe mobile device 16 is then determined (step 3102) based on informationabout each wireless beacon signal received by the mobile device 16 (step3104). This function may be provided, for example, by an indoor locationservices module, which may be located on one or more devices 14 in thedistributed lighting network 10 or remote to the distributed lightingnetwork 10 and accessed via a LAN or WAN as discussed above. Thewireless device 14 may provide a desired destination within the indoorspace (step 3106). The desired destination may be provided via inputfrom a user, for example, from an application running on a smartphone.In response to the desired destination, directions are determined fromthe location of the mobile device 16 to the desired destination in theindoor space (step 3108). These directions may be provided to the mobiledevice 16 (step 3110) such that the mobile device 16 may display them toa user.

FIG. 59 is a call flow diagram illustrating the process discussed abovewith respect to FIG. 58. As discussed above, each one of the lightingfixtures 14A provides a wireless beacon signal to the mobile device 16(step 3200). The mobile device 16 then provides information about thewireless beacon signals to the indoor location services module 114 (step3202). In particular, the mobile device 16 may provide the lightingfixture 14A from which the wireless beacon signal was received and thedistance information indicating a distance between the mobile device 16and the lighting fixture 14A for each one of the wireless beaconsignals. The mobile device 16 may also send a desired destination withinthe indoor space to the indoor location services module 114 (step 3204).While shown communicating directly with the indoor location servicesmodule 114, the mobile device 16 may communicate with the indoorlocation services module 114 through one or more intermediate devices,either locally or over a WAN such as the Internet. As discussed above,the functionality of the indoor location services module 114 may bedistributed throughout one or more devices 14 in the distributedlighting network 10, may be self-contained in several of the devices 14in the distributed lighting network 10, or may be located on a devicethat is not located within the distributed lighting network 10 but isaccessible therefrom, where one or more of the devices 14 in thedistributed lighting network (e.g., a border router 14D) may facilitatecommunication with the indoor location services module 114.

The indoor location services module 114 uses the information about thewireless beacon signals to determine a location of the mobile device 16(step 3206). This may involve using triangulation or any otherwell-known techniques to obtain a location of the mobile device 16 withrespect to the lighting fixtures 14A. Using the location of each one ofthe lighting fixtures 14A obtained above and/or the map of the indoorspace, the absolute location of the mobile device 16 may be easilyobtained. The indoor location services module 114 may further determinedirections from the location of the mobile device 16 to the desireddestination (step 3208). The location of the mobile device 16 may thenbe provided to the mobile device 16 (step 3210) along with thedirections from the location of the mobile device 16 to the desireddestination (step 3212). These directions may then be presented to auser, thereby allowing easy navigation to the desired destination. Themobile device 16 may continue to receive wireless beacon signals fromlighting fixtures 14A in the distributed lighting network 10 and provideinformation about the wireless beacon signals to the indoor locationservices module 114 such that the location of the mobile device 16 iscontinually updated, thereby enabling “turn-by-turn” indoor navigationon the mobile device 16.

In some applications, the wireless beacon signal may be broadcast by themobile device 16 and received by each one of the lighting fixtures 14A,rather than the opposite. FIG. 60 illustrates such an embodiment inwhich the mobile device 16 provides a wireless beacon signal BEAC thatis received by each one of the lighting fixtures 14A. As discussedabove, the wireless beacon signal indicates the mobile device 16 fromwhich it is provided and includes distance information indicating anapproximate distance of the mobile device 16A from the lighting fixture14A receiving the wireless beacon signal.

FIG. 61 is a flow chart illustrating one way in which this may beaccomplished. First, the mobile device 16 provides a wireless beaconsignal as discussed above (step 3300). The location of the mobile device16 is then determined (step 3302) based on information about eachwireless beacon signal received by the lighting fixtures 14A (step3304). This function may be performed, for example, by the indoorlocation services module 114 discussed above. The wireless device 14 mayprovide a desired destination within the indoor space (step 3306). Thedesired destination may be provided via input from a user, for example,from an application running on a smartphone. In response to the desireddestination, directions are determined from the location of the mobiledevice 16 to the desired destination in the indoor space (step 3308).These directions may then be provided to the mobile device 16 (step3310) such that the mobile device 16 can display them to a user.

FIG. 62 is a call flow diagram illustrating the process discussed abovewith respect to FIG. 61. As discussed above, the mobile device 16provides a wireless beacon signal to each one of the lighting fixtures14A (step 3400). Each one of the lighting fixtures 14A then providesinformation about the wireless beacon signal from the mobile device 16to the indoor location services module 114 (step 3402). As discussedabove, the lighting fixtures 14A may provide information to the indoorlocation services module 114 indicating the mobile device 16 from whichthe wireless beacon signal was provided and the distance informationindicating a distance between the lighting fixture 14A and the mobiledevice 16. While shown communicating directly with the indoor locationservices module 114, the lighting fixtures 14A may communicate with theindoor location services module 114 through one or more intermediatedevices, either locally or over a WAN such as the Internet. The mobiledevice may also send a desired destination within the indoor space tothe indoor location services module 114 (step 3404). While showncommunicating directly with the indoor location services module 114, themobile device 16 may communicate with the indoor location servicesmodule 114 through one or more intermediate devices, either locally orover a WAN such as the Internet. The indoor location services module 114uses the information about the wireless beacon signals to determine alocation of the mobile device 16 (step 3406). This may involve usingtriangulation or any other well-known techniques to obtain a location ofthe mobile device 16 with respect to the lighting fixtures 14A. Usingthe location of each one of the lighting fixtures 14A obtained aboveand/or the map of the indoor space, the absolute location of the mobiledevice 16 may be easily obtained. The indoor location services module114 may further determine directions from the location of the mobiledevice 16 to the desired destination (step 3408). The location of themobile device 16 may then be provided to the mobile device 16 (step3410) along with the directions from the location of the mobile device16 to the desired destination (step 3412). These directions may then bepresented to a user, thereby allowing easy navigation to the desireddestination. The mobile device 16 may continue to provide wirelessbeacon signals to the lighting fixtures 14A, which update the indoorlocation services module with updated information about the wirelessbeacon signals such that the location of the mobile device 16 iscontinually updated, thereby enabling “turn-by-turn” indoor navigationon the mobile device 16.

While the aforementioned ways to provide indoor location services to amobile device 16 are primarily discussed with respect to the use ofwireless beacon signals, other ways to track the mobile device 16 and/ora user of the mobile device within the indoor space may be used eitherin conjunction with or in lieu of the wireless beacon signals in someembodiments. For example, cameras on the lighting fixtures 14A may beused to track the location of a user within the indoor space and providedirections to a mobile device 16 thereof in some embodiments.

Those skilled in the art will recognize improvements and modificationsto the preferred embodiments of the present disclosure. All suchimprovements and modifications are considered within the scope of theconcepts disclosed herein and the claims that follow.

What is claimed is:
 1. A method for locating devices in a distributedlighting network, the method comprising: obtaining a set of distancemeasurements between each of a plurality of devices connected to thedistributed lighting network; determining whether the set of distancemeasurements is incomplete; when the set of distance measurements isincomplete, pre-processing the set of distance measurements to produce acomplete set of distance measurements; obtaining environmentalmeasurements from sensors connected to the distributed lighting network;and determining a location of each device connected to the distributedlighting network based on the complete set of distance measurements andthe environmental measurements.
 2. The method of claim 1, whereindetermining whether the set of distance measurements is incompletecomprises verifying whether a measurement exists between each of theplurality of devices.
 3. The method of claim 1, wherein determiningwhether the set of distance measurements is incomplete comprisesdetermining whether any of the set of distance measurements is longer orshorter than expected.
 4. The method of claim 3, wherein pre-processingthe set of distance measurements comprises discarding any of the set ofdistance measurements that is longer or shorter than expected.
 5. Themethod of claim 1, wherein pre-processing the set of distancemeasurements comprises calculating one or more missing distancemeasurements.
 6. The method of claim 1, wherein pre-processing the setof distance measurements results in groups of lighting fixtures withcoordinates relative to one another.
 7. The method of claim 6, furthercomprising merging the groups of lighting fixtures which overlap oneanother.
 8. The method of claim 1, wherein the set of distancemeasurements is obtained from at least one mobile device based onwireless beacon signals emitted by lighting fixtures in the distributedlighting network.
 9. The method of claim 8, further comprising:determining directions from a location of the at least one mobile deviceto a destination in a space covered by the distributed lighting network;and communicating the directions to the at least one mobile device. 10.A distributed lighting network, comprising: a plurality of lightingfixtures, each of which is configured to emit a wireless beacon signalindicating a distance measurement to another lighting fixture or device;and a location services module in communication with each of theplurality of lighting fixtures and configured to: receive a set ofdistance measurements between each of the plurality of lighting fixturesor devices based on each wireless beacon signal; determine whether theset of distance measurements is incomplete; when the set of distancemeasurements is incomplete, pre-process the set of distance measurementsto produce a complete set of distance measurements; and determine alocation of each lighting fixture or device connected to the distributedlighting network based on the complete set of distance measurements. 11.The distributed lighting network of claim 10, wherein the locationservices module is configured to determine whether the set of distancemeasurements is incomplete by at least one of: verifying whether ameasurement exists between each of the plurality of devices; ordetermining whether any of the set of distance measurements is longer orshorter than expected.
 12. The distributed lighting network of claim 11,wherein the location services module is configured to pre-process theset of distance measurements by calculating one or more missing distancemeasurements.
 13. The distributed lighting network of claim 10, whereineach wireless beacon signal indicates the one of the plurality oflighting fixtures that emitted the wireless beacon signal and a distancebetween a receiving device and the one of the plurality of lightingfixtures that emitted the wireless beacon signal.
 14. The distributedlighting network of claim 10, wherein the indoor location servicesmodule is further configured to facilitate generation of a graphicalrepresentation of an indoor space based on the location of each one ofthe plurality of lighting fixtures
 15. The distributed lighting networkof claim 10, wherein the indoor location services module is furtherconfigured to determine the location of each lighting fixture or deviceconnected to the distributed lighting network by: assigning relativecoordinates to each one of the plurality of lighting fixtures, whereinthe relative coordinates indicate a relative location of each one of theplurality of lighting fixtures with respect to one another; facilitatingregistration of the relative coordinates assigned to a subset of theplurality of lighting fixtures to obtain registered coordinates for thesubset of the plurality of lighting fixtures; and interpolating theregistered coordinates for the relative coordinates of the ones of theplurality of lighting fixtures not in the subset of the plurality oflighting fixtures
 16. A controller for a distributed lighting network,comprising: communications circuitry configured to couple to a pluralityof devices in the distributed lighting network; and processing circuitrycoupled to the communications circuitry and configured to: obtain a setof distance measurements between each of the plurality of devicesconnected to the distributed lighting network; determine whether the setof distance measurements is incomplete; when the set of distancemeasurements is incomplete, pre-process the set of distance measurementsto produce a complete set of distance measurements; obtain environmentalmeasurements from sensors connected to the distributed lighting network;and determine a location of each of the plurality of devices based onthe complete set of distance measurements and the environmentalmeasurements.
 17. The controller of claim 16, comprising a locationservices module for the distributed lighting network.
 18. The controllerof claim 17, wherein the set of distance measurements is based onwireless beacon signals transmitted from each of a plurality of lightingfixtures in the distributed lighting network.
 19. The controller ofclaim 16, wherein the processing circuitry is further coupled to one ormore sensors configured to provide the environmental measurements. 20.The controller of claim 19, wherein the processing circuitry is furtherconfigured to determine the location of each of the plurality of devicesbased on the environmental measurements.